COPS AND DOGS AGAINST PARTY DRUGS

Several hours before the start of the yearly ‘Free Your Mind’ techno festival, we report to the coordinator of today’s ‘Operation Zero Tolerance’. The hastily erected police post is already a hive of activity. The rave grounds lie amidst a park-like landscape on the banks of the Rhine and not far from the historic Arnhem Bridge of World War II fame. The organisers, expecting a crowd of 10.000, can feel pleased with the warm summer’s day that awaits them. But they are less happy about the police announcement that today’s festival-goers will be sniffed by drug hounds. The police post is strategically located right next to the festival entrance. Slightly further along, four arrest vans and three vehicles from the canine brigade are parked next to an old, converted city bus that will serve as a coordination post. In the rear of the bus, a makeshift strip-search cubicle has been fitted out, partitioned off with a wrinkled curtain. This year, the windows have been blacked out too, after complaints by detainees at last year’s festival. At the centre of the cordoned off plot of ground measuring 50 square metres at most, two long tables have been set up, bearing stacks of pre-numbered charge sheets and dismissal sheets, three Polaroid cameras and several boxes of gloves (to avoid touching confiscated drugs and confusing the drug sniffer dogs). The domain in question is off-limits to anyone except police officers and detained suspects, who today will be subject to on-the-spot justice and immediately brought before a public prosecutor. Extra cells have been freed up in the city.


Introduction 1
Several hours before the start of the yearly 'Free Your Mind' techno festival, we report to the coordinator of today's 'Operation Zero Tolerance'.The hastily erected police post is already a hive of activity.The rave grounds lie amidst a park-like landscape on the banks of the Rhine and not far from the historic Arnhem Bridge of World War II fame.The organisers, expecting a crowd of 10.000, can feel pleased with the warm summer's day that awaits them.But they are less happy about the police announcement that today's festival-goers will be sniffed by drug hounds.The police post is strategically located right next to the festival entrance.Slightly further along, four arrest vans and three vehicles from the canine brigade are parked next to an old, converted city bus that will serve as a coordination post.In the rear of the bus, a makeshift strip-search cubicle has been fitted out, partitioned off with a wrinkled curtain.This year, the windows have been blacked out too, after complaints by detainees at last year's festival.At the centre of the cordoned off plot of ground measuring 50 square metres at most, two long tables have been set up, bearing stacks of pre-numbered charge sheets and dismissal sheets, three Polaroid cameras and several boxes of gloves (to avoid touching confiscated drugs and confusing the drug sniffer dogs).The domain in question is off-limits to anyone except police officers and detained suspects, who today will be subject to on-the-spot justice and immediately brought before a public prosecutor.Extra cells have been freed up in the city.
The members of the police squadron, which numbers 70 officers at the morning briefing, are 25 to 35 years of age, making them age peers of the ravers who will attend the festival.When the assistant prosecutor asks how many officers have experience with this zero tolerance approach, conspicuously few raise their hands.Most members of the police team are trainees; they are predominantly male and scarcely distinguishable from real partygoers.They are dressed in fashionable faded combat bottoms and colourful T-shirts stamped with vivid images, snazzy sunglasses, training shoes and Timberland boots.A small group of hyper hip police officers traipse about, scantily clad in see-through vests, and many of them sporting awesome tattoos.This group of officers will mingle as inconspicuously as possible with the ravers, who must walk down a 500-metre path from the car park to reach the event grounds, where they will be awaited by the sniffer dogs.Spirits in the police team are high."Today we're tolerating nothing at all!" we hear the assistant prosecutor warn in his pep talk.The detective work concentrates mainly on the queues outside the entrance to the event and on the pathway leading to the festival grounds.The 'snatch teams' work in liaison with the excessively hip undercover agents.The teams are also unrecognisable to the general public (we recognise them by their goldcoloured wrist bands).
They loiter about amongst groups of ravers, pretending to wait for their 'friends'.Their orders are to spot people that 'act suspiciously' or that 'openly' take drugs along the approach route to the event.The police watchword at 'Free Your Mind' is 'zero tolerance'.The festival-goers are little aware of what is in store for them.Police will later report in a press release that 91 persons were detained that day for possession of drugs.In most cases, these were tiny amounts of ecstasy, cocaine or GHB.Some 56 detainees were brought before the prosecution and received fines or court summonses.The largest amount of drugs seized consisted of 54 ecstasy tablets and a small amount of GHB.More than 100 ravers brought in for possessing cannabis were released due to the small amounts, and the police recorded neither their names nor the amounts of cannabis seized -which we estimated at 200 to 300 grams in total.According to our observations, not 91, but approximately 200 people were detained.Half of them were in possession of cannabis only and the other half were carrying small amounts of banned substances. 2 These observations reflect in a nutshell the problems that confront many Dutch event organisers today.Since 2005, zero tolerance is the keyword, especially during the peak summer season for dance events.Regular reports on drug use at dance parties have appeared in the media since then, repeatedly reconfirming the notoriety of the events as hotbeds of drug use. 3n the period 2005-2008, the estimated number of arrests on suspicion of possession, selling or public consumption of drugs ran into the thousands; these mostly involved very small amounts of drugs. 4Curiously enough, this large number of arrests contrasts sharply with the sustained decline in drug use and drug-related incidents in the Netherlands in the past decade.The highest rate of ecstasy use by far was reported in 2001-2002 among dance party attendees. 5Especially in the years that followed, drug use at such events declined significantly, as did the numbers of drug-related health incidents.The decline was due in part to tighter regulation and to the professionalization of the dance industry. 6though the basic premises of the Dutch two-track policy on drugs -health promotion and harm reduction with respect to drug use combined with repressive measures towards the drug trade -are still in place, researchers conclude that the margins are narrowing.Regulations have been toughened, policies of toleration have been withdrawn, and the approach to groups that take drugs has hardened in comparison to the 'tolerant' attitude that was previously favoured. 7hree questions present themselves: (1) What is the effect of zero tolerance in practice?(2) How have drug users and drug dealers reacted to the repressive measures, which sometimes include drug detection dogs?(3) What developments have occurred in the drug trade and in the use of recreational substances?

I. Research Strategy
To shed more light on the dynamics and effects of the zero tolerance approach to drug use at Dutch dance events, I will explore here in particular the interplay between stringent law enforcement and the behaviour of partygoers.I do so using qualitative research methods, including participant observations, field notes (including a topic list), semi-structured interviews with experts, and informal chats, polls and interviews with partygoers about their drug use in relation to the zero tolerance policies.
In the summer of 2008, a research team from the Bonger Institute of Criminology attended 19 large dance events where a zero tolerance strategy was being pursued.With police approval, our fieldwork team watched 'over the shoulder' of the police as they implemented the zero tolerance policy at two of the events.We focused primarily on police strategy and working methods, such as strip-searching partygoers, deployment of drug sniffer dogs and procedures to process suspects.We interviewed drug dog handlers, public prosecutors, arrest teams, door staff and partygoers. 8At one party, we covertly observed the methods and conduct of a police drugs intervention team.9Certain drawbacks of covert observation have been pointed out in the literature10 -mainly that the researchers obtain only limited information.Yet one could also argue that police conduct may be influenced if researchers identify themselves.Through covert observation we could observe the working methods of the plainclothes police as 'naturally' as possible.
At six of the dance events, we also collected information regarding the drug users' perspective.In cooperation with Unity, a voluntary project providing drugs education at many large events, we administered questionnaires to partygoers which also included a multiple-choice question to detect any behavioural changes in drug users that might have resulted from the restrictive policies.These quantitative data were statistically analysed (SPSS).Invoking the Government Information (Public Access) Act (WOB), we later also obtained and then analysed several police reports (with both qualitative and quantitative data) filed by drugs intervention teams; that information is discussed here in the context of field observations and interviews with police officers, door staff and partygoers at large dance events.

II. Zero Tolerance -an Utopia?
Does stricter drug detection by security staff and police (using sniffer dogs and plainclothes teams) lead to an actual reduction of drug use and drug dealing at dance events?Does a rigorous 'zero tolerance policy' act as a deterrent, or does it mainly produce a 'waterbed effect' in practice by shifting the problem somewhere else?Before exploring these issues in more detail, I will first review the international criminological literature on zero tolerance.The concept of zero tolerance can be traced genealogically to Reagan era in the 1980's USA, as the 'War on Drugs' took shape in the campaign against the 'crack epidemic'.11Zero tolerance was strongly inspired by the 'broken windows approach' to crime prevention, which postulates that stringent formal police control of minor offences will foster stronger informal control amongst individual members of the public, thus leading to a reduction of crime. 12Hence, the core belief underlying the broken windows theory and zero tolerance is that strict formal control of crime will result in strong informal controls.If we transpose this onto party drugs, then 'zero tolerance' enforced through formal control by both police and event organisers should elicit informal social control amongst the ravers themselves.Theoretically, the resultant self-correcting behaviour should precipitate a sharp decline in drug dealing and drug use, under the motto 'A party without drugs can also be fun!' Some criminologists have called into question whether 'zero tolerance' is as successful as police and politicians in the 1990's claimed it to be as a weapon against crime, using New York as the classic symbol.Zimring 13 has argued that the crime reduction in New York in the 1990's was already underway before the zero tolerance or broken windows approach was introduced.The preceding period had been characterised by a drastic reorganisation of the police force, a massive increase in the numbers of officers and a bolstering of community policing.The fact that the crime rate continued to decline after the switch to zero tolerance can be explained, according to Zimring, by demographic trends whereby the group of adolescents and young adults of crime-sensitive age (15 to 29) was shrinking.Two other US criminologists 14 have concluded that the sharp drop in the number of fatal young victims of violent crime in Boston during zero tolerance can definitely be explained in part, if not primarily, by the powerful, non-repressive social outreach efforts of religious leaders and community residents.A study by Young 15 has furthermore shown that the crime rates in states, that did not adopt 'zero tolerance' policies, also substantially declined.It is therefore highly debatable whether the declining crime rates in the United States were caused by zero tolerance.
Newburn and Jones 16 suggest several reasons why policymakers and law enforcement officials continue to avidly believe in their 'zero mission'.'Zero tolerance' is a popular, catchy notion that leaves no room for doubt and can be flexibly applied in many different situations without having to be clearly defined.It has a strong symbolic potential and it resonates well with the current problems and ostensible solutions as articulated by politicians, populists and police.According to the criminologists Hayward17 and Ferrell & Sanders, 18 it would seem as if the authorities use 'zero tolerance' to create their own 'criminal momentum' and to call attention to what they perceive as massive violations of rules.This same attitude is reflected in the Dutch 'zero tolerance' approach to drugs at dance events.In the permits issued to the event organisers, the police stipulate that the events must be drug-free.If the organisers fail to achieve this, they will be called to account at the evaluation and/ or on the next occasion when they apply for a permit.Many researchers are sceptical about the authorities' general aspirations to exert substantial influence on the scale of illegal production, sale and use of drugs. 19However, since studies like theirs are usually based on global or national statistics, it seems reasonable to ask whether those general conclusions are also valid in local situations and in specific settings like dance events.Moreover, even if government policies do lack influence on the scale of drug dealing and drug use, that does not mean that the policies have no effects at all on these phenomena.

III. Zero Tolerance in Practice
The policies of toleration that were pursued in the Netherlands until far into the 1990's were superseded in the following decade by a tougher line -a reversal that Das has portrayed as 'the changing soul of Dutch policing'. 20In what Das terms a 'moral civilising offensive', 'zero tolerance' is the crowning principle.More forcefully than before, the Dutch government launched a concerted effort to curtail the 'normalisation of drug use' (the increasing acceptance of drugs amongst young people).The criminologist Korf, 21 however, has warned that the normalisation of drug use appears to largely unfold as a spontaneous social process, relatively independent of national drug policy."Policy that aims to de-normalise drugs therefore seems doomed to get stranded in moral rhetoric." A full-blown zero tolerance operation consists of a large contingent of police officers accompanied by drug sniffer dogs and arrest vans and a 'washeteria' specially fitted out for the on-the-spot imposition and settlement of fines.The number of people arrested may range from several dozen into the hundreds per location.The vast majority are users or possessors of small amounts of drugs (mostly cannabis or ecstasy, and sometimes speed, cocaine or GHB); rarely are any 'big fish' discovered amongst them. 22Partygoers who have bought cannabis beforehand in a legally tolerated coffee shop may be forced to surrender it to door staff or security personnel before entering the event, or they may be snuffled out by drug hounds and then strip-searched for possession of other drugs. 23ugs Intervention Team (HIT) reports have revealed that the police were highly displeased about alleged continual failures on the part of event organisers and security firms to comply with commitments. 24The reports accuse the organisers and security firms of poorly communicating with partygoers about the 'zero tolerance' policy.The 'drug drop boxes' at the entranceways were not placed sufficiently in view.The body searches by door staff and security personnel were 'hardly impressive' and contributed little to keeping narcotics off the premises.The organisers then received further instructions down to the smallest detail about what was not suitable and had to be improved.The information derives from the HIT reports obtained under the Government Information (Public Access) Act (WOB), as well as from accounts of police operations in 2009 on the culture ship Stubnitz and at the Loveland Festival.The report entitled 'Evaluatie Loveland Festival 2009/2010', produced by the festival organisers in response to the written evaluation by the police and to the HIT report, revealed sharp differences of opinion between organisers and police on a variety of issues: the proper way to deal with open or covert drug use by festival-goers, surveillance on the festival grounds, communication of the festival's policy on drugs to its patrons, entry checks, and surveillance around lockers and toilets.An example is the police allegation that the drugs policy was not adequately communicated to the attendees.In their reply, the organisers reported that they had hung up posters at the festival entrance stating house rules, including (in Dutch) 'ZERO TOLERANCE POLICY -NO HARD OR SOFT DRUGS ALLOWED'.This was also communicated on external websites, in a press release, in e-mailings, and in a warning (in English) on the ticket order page of their own website: 'NO DRUGS ARE ALLOWED AT LOVELAND FESTIVAL.THERE IS A ZERO TOLERANCE POLICY'.The fact that no clarity existed as to what was understood by 'adequate communication' apparently gave police the right to continuously expect or demand new measures from festival organisers.
Three dilemmas or operational difficulties tend to arise in putting zero tolerance into practice at large events.From the organisers' point of view, the desire for a rapid flow of crowds into the event at peak periods clashes with the stringent body searches at the entrance as demanded by police.Hence, in the eyes of the police, the security staff does not undertake enough action against drug use and drug dealing.At the same time, the police do acknowledge a second dilemma -the limitations on the actions that security staff is allowed to take.Police are aware that partygoers often conceal drugs in their underwear and that security staff are not allowed to search there.Nor is staff of private security firms allowed to work in plain clothes.However, we learned in interviews with security staff at several events that they see their primary task as maintaining order at the event rather than as intercepting as many drugs as possible.A third dilemma involves the number of staff to be deployed.To the event organisers, this is obviously an issue of cost control.But the drugs intervention squad itself observes that 'this method of policing drug dealing and drug use is a virtually endless mission' for the police force.By their own account, there is 'never enough personnel' to act against the trade and consumption of drugs, which is said to reach 'enormous proportions' in the course of the evening.What is clear in any case, then, is that the 'zero tolerance' strategy at dance events is not completely watertight.Nevertheless, police do make arrests and do confiscate drugs.

IV. Reactions of Partygoers
According to the police reports on operations at large dance parties, the efforts of security staff and police evidently failed to keep many partygoers from bringing in drugs and consuming them (though this often happened covertly).Security staff recounted inventive 'smuggling methods'."If ravers want to bring in drugs, they'll succeed," an experienced security worker remarked, "it's Mission Impossible."In an Australian study on the effectiveness of using dogs to track down drug dealers at large events, Dunn and Degenhardt25 concluded that many partygoers who were suspected of drug dealing were actually just ordinary possessors.Half of the ecstasy users reported taking extra advance precautions by hiding their drugs better if they thought there would be sniffer dogs at events.One quarter took drugs before entering the festival grounds.Other precautions were avoiding areas where sniffer dogs were operating and carrying only minimal amounts of drugs.Only a few respondents reported discarding their drugs or buying drugs at the event.One out of five reported not bringing any drugs to the event.A large majority, however, said they would bring drugs with them to subsequent parties in spite of the tougher sanctions.
A similar picture emerged from our own fieldwork and from brief surveys by Doekhie and colleagues (2010) of more than 400 people attending six Dutch dance events. 26A wide majority of the partygoers reported that they continued to take drugs just as before.They estimated the chances of getting arrested as small.Despite the reported indignation, the crowds at the events generally shrugged their shoulders at the presence of police and sniffer dogs.Most people offered no resistance and kept their cool during interrogations.If they did respond critically to the measures, they received sharp rebukes.Some people were very upset and called the body searches 'intimidating', 'senseless' or 'harassment'.Others were embarrassed by being strip-searched.Many of the searches proved unwarranted -a finding consistent with those of Tobin, who concluded that three quarters of ravers were questioned and searched unnecessarily. 27 a general rule, it seems that the tighter the screening, the more drugs that are consumed before an event starts.A large majority of drug users make arrangements for their drugs prior to the event.The brief surveys referred to above of partygoers (most of whom were users of party drugs) showed that most, but not all, of the drug users anticipated the drug checks.Their primary response was to conceal their drugs better than previously and secondly by taking pills or snorting cocaine before the party.To a lesser extent, they responded to the stricter control by not carrying enough drugs to get fined and/ or by obtaining drugs at the event.Only a small group of partygoers went out in search of pills or other drugs at the event.Another small minority considered no longer bringing drugs with them to a festival. 28

V. Social Interaction and Cohesion at Dance Events: Sharing or Dealing?
As discussed earlier, most people who get caught in possession of drugs at dance events have only small amounts of drugs with them.There is a good explanation for this.Many go there in small groups.A shared preference for a particular type of music creates a social bond between kindred spirits in a 'temporary party community'. 29In his book Interaction Ritual Chains, the sociologist Collins 30 describes several preconditions under which a 'collective effervescence' is generated: a mutual focus, a shared mood, physical density, and barriers to the involvement of outsiders.Often a strong social empathy arises between 'friends' and 'strangers'.New contacts are made spontaneously, as between neighbours.At a dance party, strangers sometimes feel like friends for life.People admire one another's tattoos and jewellery, they exchange addresses, and they come to each other's aid if they pass out.This sense of altruism stands in stark contrast to the cultural pessimism propagated in writings about the anxious, atomised individual.Reciprocity between partygoers, the exchange of objects without pursuit of profit, is often observed.A cigarette, a sweet, an ice lolly, chewing gum or a piece of jewellery may be offered spontaneously or exchanged for something else.If you are thirsty on the dance floor, someone offers you a sip of water.iPods, iPhones and Blackberries are compared, as are the size of eye pupils (reflecting which drugs have been taken and what amounts).The ravers 'go with the flow', melt into a pulsating mass of dancing people, ride the waves of the music.
Grossly out of place in this revelry are the activities of 'outsiders' or 'flow breakers' like bouncers, uniformed officers and plainclothes police.To an officer trying to spot drug taking or drug dealing, a simple caress, a kiss, a cuddle, a grope into a pocket (for a mobile phone, tissue, calling card, condom, cigarette or cough drop) can easily be construed as a suspicious act.Remarkably, the reports of the police drugs team that we read did not describe a single case of money changing hands, but did mention numerous instances of 'drug dealers' activities'.The goings-on we observed indicated that such gestures rarely involve 'real' drug transactions, but mainly reciprocal exchanges or gifts with non profit motive.Hence, it is mainly sharing rather than dealing.31'Real' drug dealing is uncommon, because groups of partygoers are usually self-sufficient in terms of any provisions they need.
In the light of the atmosphere of solidarity that arises between partygoers at large dance events, why are so few protests heard from the people who are subjected to body searches (whether or not justified) and who are sent through the 'washeteria'?Moreover, why do bystanders keep their cool?The most obvious explanation is that they put it down to bad luck.Or they think 'Serves you right', because if you flaunt being high on drugs, you may catch the eye of the police and risk getting searched.Partygoers report that the drug checks and plainclothes police have negative effects on the atmosphere, inhibit spontaneity, and spark a fear of being watched if you take a pill or start tripping.Indeed, it can be very upsetting to get detained if you have no drugs on you.A small joint may be enough to trigger a thoroughgoing body search.But distressing as that may be, people try to not let it spoil their party.

VI. Trends in Drug use and Zero Tolerance
The 'zero tolerance' crackdowns in Dutch nightlife are not without precedent.So far, developments have predominantly been discussed at national level, but in this section the focus will be mainly on Amsterdam.Some years back, popular Amsterdam dance clubs were closed down after police raids.Other measures were 'clean-ups' in the bouncers' milieu, body searches in clubs, drug drop safes, the programming of urban rather than house music, and the banning of cannabis in clubs.A 'new sobriety' began to catch on in nightlife; being conspicuously stoned in public was increasingly 'not done'. 32A new generation of night lifers was also less amenable to partying every weekend, and the changing mores in the clubs increasingly thinned out the subculture of ecstasy users.Some of them began using cocaine, which has a shorter high than ecstasy and is therefore better suited to settings that are less dance-oriented, such as cafés, bars, private parties or home settings.It is difficult to determine, however, whether there is a causal association between repressive measures and such trends in drug use.
In a process of 'controlled' drug use, as observable in these nightlife scenes, the setting in which the drug use takes place plays a critical role, enabling the drug users to develop informal rituals and sanctions.Drug use is commonly accompanied by informal norms and concomitant behavioural rules (such as about how, where and with whom drugs will be taken), and behavioural patterns are shaped by trial and error.Harding and Zinberg 33 argued that one function of rituals and social sanctions associated with substance use is to minimise untoward effects.As a peer group learns to take drugs in a 'controlled' fashion, it applies informal rules and sanctions, such as 'not too often' and 'not too much at a time'. 34 exerting more formal control, the zero tolerance strategy also seeks to strengthen informal social control, with drug-free nightlife as the ultimate goal.Clearly this goal has not been achieved.Although drug use in Amsterdam nightlife has declined, that trend was already underway when the zero tolerance policy was initiated.As we have seen, some people who used to take drugs at dance events, albeit a small percentage, have decided to refrain from taking drugs altogether at the parties as a response to the clampdown.The main reaction, however, has been to circumvent the repressive measures as much as possible -and often successfully.This may be due in part to the inadequacy of 'zero tolerance' as practiced at the dance events.Yet even before 'zero tolerance' was launched, some ravers were already taking drugs before going to parties to get into the mood 35 : as van den Hazel (2008) has shown, some types of partygoers tend to arrive at dance events already under the influence, regardless of what door policies are in place. 36

Conclusion
Dutch law enforcement authorities have been increasingly visible at dance events in recent years, especially in regions that frequently host such events.One clear policy reversal is that the possession of cannabis (even in amounts below 5 grams) is no longer being tolerated at these events; marijuana and hashish are often confiscated on the spot.Increasingly, 'washeterias' are set up to process the streams of detained suspects as efficiently as possible and refer them to the public prosecutor on duty for a charging decision.Anyone caught with a punishable quantity of drugs is offered the opportunity to pay a fine on the spot.Especially in popular dance event regions, drug detection sniffer dogs are increasingly deployed at entranceways and along the queues waiting outside.
Although the policy has little support among partygoers, there have been no major protests about the fact that hundreds of partygoers have been strip searched and fined for possession of drugs (but rarely for dealing) in recent years.In order to not let the police spoil their party pleasures and to prevent the pains of arrest, the predominant reaction from drug users at such events has been to elude or outfox the drug checks by taking drugs beforehand and/ or by hiding their drugs better before entering the event.Another group, albeit a minority, have decided to attend the parties without drugs in response to the checks.
It is patently clear that the 'zero tolerance' operations at dance events are not watertight.Party drug users still succeed in smuggling in drugs.The 'zero tolerance' strategy seems to have had little effect on the scale of drug use.A majority report that they continue to take drugs in spite of the 'zero tolerance' policy.Bringing in drugs is not only a question of hiding them effectively.There are also legal limits on how far security staff may go, such as how intimately they can search people.Moreover, far more police and party staff would be needed to thoroughly search all the people attending.Even leaving aside the prohibitive costs of the latter operation, it would raise formidable problems with maintaining order.When drugs change hands at parties, the users themselves often perceive that as exchanging or sharing -contrary to police insinuations of widespread drug dealing -because such 'trading' is usually not done for profit.The general rule seems to be the stricter the policing, the more drugs that are taken in advance of an event.
It is quite conceivable that the stricter surveillance in Dutch nightlife could result in a moderation of drug consumption over the longer term and to a displacement of drug use to more private settings.In the latter case, we have seen that changes of setting may also imply changes in the nature of drug use -sniffing cocaine, for instance, rather than taking ecstasy.But on the basis of the current data it is not possible to determine whether such changes are causally connected to the shifting drug policies.
Nederland 2004-2005, Amsterdam: Rozenberg 2005.And: T. Nabben, A. Benschop & D. J. Korf, Antenne 2005.Trends in alcohol, tabak en drugs bij jonge Amsterdammers [Antenne 2005.Trends in the use of alcohol, tobacco and illicit drug among young people in Amsterdam], Amsterdam: Rozenberg 2006. 36D. van den Hazel, Politie aan je broek.Een onderzoek naar de invloed van het strengere drugsbeleid op grootschalige dance-evenementen op de smokkel van, de handel in en het gebruik van drugs [A study about the influence of a more repressive drug policy on large-scale dance events on drug trafficking and drug use], Leiden University, Department of Criminology (unpublished master thesis) 2008.