It is well known that Canada's prostitution laws made Robert Pickton's crimes easier to commit. The laws make it so that sex workers have to maintain secrecy about every aspect of their lives, evade questions by police about their friends, and not having a steady routine or being at the same place. 

Street prostitutes face daily random assaults, from straight out rape to having things thrown at them from passing cars, but if they run it from their own house, the house will get seized, so they are forced onto the street or risk losing everything they work for. 

   It is also well known that Canada's prostitution laws make it much easier for gang pimps and child sex rings to operate, because by 'keeping the net wide', as police would like to do, means that police sting operations can 'make more busts' by targetting individual women operating independant businesses because they're easier to catch and easier to determine whose assetts are being seized and where to find those assetts. Gangs are notoriously good at covering their paper trails, because they have networks of people to keep money with and keep houses in different names so the 'mob boss' owns nothing on paper.

Gangs can use their numbers and money to bribe and/or intimidate police, prosecutors, politicians and judges while independant women have no such advantages. 

    So police have allowed the gang pimps and child sex rings to carry on with little or no interference, because they prefer the easy job of robbing  poor women for everything they earn, and then forcing them into 'rehabilitiation programs' where 'prostitution experts', mostly religious crazies of some sort or another as well as elitist radical feminists and a few former gang-controlled prostitutes to put in front of the cameras, all of whom simply refuse to believe women would choose high paying independant sex work over low paying service jobs, lecture them on how much more dignity and self-worth they'll have waiting tables for minimum wage. 

   Thanks to the courage of sex workers who faced longer sentences and continued legal pressure and blatant persecution, largely from women who make their living at various points in the legal system 'helping' prostitutes against their will,  in addition to other stresses, these problems were brought to the supreme court in 2009 by sex worker Terri-Jean Bedford through well known 'activist' lawyer Alan Young. In 2010 the case was won, with the laws being thrown out but subject to appeal by the Federal Government. The ruling was supported by Green Party leader Elizabeth May,  Liberal Party leader Justin Trudeau,  no comment from NDP leader Thomas Mulcair and hostile yet smirking resistance from Stephen Harper. Needless to say, the Federal Government immediately appealed , and now the appeal has finally ended and parliament has one year to find a realistic strategy to regulate the sex trade so that the safety of sex workers is a priority and the gangs that enslave women and girls against their will can be the primary targets of police, and police can target those criminals with willing and honest assistance from sex-workers themselves, who are currently under constant threat from both sides of the law if they inform on the darker elements that exist on the fringes of the profession. Allowing consensual adult sex workers to have safety and security, physically and economically, will disempower the gangs that try to control the profession, and possibly take a piece out of organized crime's revenue as well. 

"The purpose of the living on the avails of prostitution prohibition ... is to target pimps and the parasitic, exploitative conduct in which they engage. The law, however, punishes everyone who lives on the avails of prostitution without distinguishing between those who exploit prostitutes and those who could increase the safety and security of prostitutes, for example, legitimate drivers, managers, or bodyguards. The living on the avails provision is consequently overbroad." 

"The purpose of the communicating prohibition ... is not to eliminate street prostitution for its own sake, but to take prostitution off the streets and out of public view in order to prevent the nuisances that street prostitution can cause. The provision’s negative impact on the safety and lives of street prostitutes, who are prevented by the communicating prohibition from screening potential clients for intoxication and propensity to violence, is a grossly disproportionate response to the possibility of nuisance caused by street prostitution."  

- Chief Justice Beverley McLachlin, in the decision. Read the full Supreme Court decision, PDF.

For more on the struggle from the perspective of the sex workers themselves, here is Sex Worker and advocate "Venus" from The Toronto Sex Workers Action Project speaking at The International Prisoner's Justice Day Vigil, Don Jail, Toronto, August 10, 2012:   http://www.mediacoop.ca/video/venus-sex-workers-action-project-toronto-speaking/20498

References: 

http://maggiestoronto.ca/press-releases?news_id=114

http://www.huffingtonpost.ca/2011/10/18/pickton-inquiry-antiprostitution-laws_n_1018149.html

http://www.cbc.ca/news/politics/supreme-court-strikes-down-canada-s-prostitution-laws-1.2471572

http://www.surreyleader.com/news/236758021.html