San Francisco is the perfect example of what happens when you house addicts - they don't improve, continue the bad behavior, they destroy the housing and are often kicked out of it. We've got several examples a week of people making meth in their housing and creating a severely hazardous situation.

If you check out @bettersoma on twitter he's got a looooot of info about this.

I am definitely not an expert, don't know about the data around shelters. My understanding of shelters is that they make it a lot harder to do drugs and that is why a lot of the homeless prefer camps. My understanding is that abuse, violence and drug use are reduced at shelters and that is the main advantage of them.

The shelters usually require sobriety and don't have a good track record of dealing with violent people.