Vancouver has two very well-known cop spots, as in everybody in the city knows what's going on. The first one is a park crawling with scraggly looking native guys selling expensive buds (still cheap by most tourists' standards, so they make bank). The other is one corner of the most notorious intersection in town. You can get anything you want, there are tons of homeless junkies and tweakers everywhere all fucked up out of their minds convulsing and talking to themselves, it's really quite the sight if you haven't experienced it before. Don't wear anything nice or bring a phone/wallet/anything of value unless you want to be hurt, mugged or at the very least ripped off. One very desperate day I drove downtown, parked several blocks away, and walked over to a block away from the spot. Chatted up this guy who didn't look much older than me, so a young guy, gave him a cigarette and he explained in detail how to get on methadone maintenance for free, and how InSite (safe injection center for IV drug users) works. Then I asked if he could get me any pills, and he told me he knew a guy at the notorious corner who had 100mg MS Contins, the crushable good kind. He asked how much I usually paid and I told him the truth, he said he'd match it. Five minutes later I had the pills in my hand and was walking back to the car.
So yeah, it's pretty easy to get hooked up, and not nearly as hot as it should be (considering the latter spot is literally a stone's throw away from a police station).