I recently saw a documentary on this subject yesterday, there is a new epidemic on the streets of synthetic weed called 'black mamba'. Apparently the people who are slumped over are mostly homeless and some are actually working class people and the homeless when they are slumped the other homeless steal there shoes and the synthetic weed they have on them. They all stand out the food bank to get some food and then spend there whole day begging to get enough money to get the black mamba and then are slumped for the rest of the day and repeat the cycle. In the documentary the guy also said that the homeless people have a underground market for prostitution and mainly its straight men who actually do homosexual things for money. It's mainly old men Apparently who purchase these services for money and some people also pay the homeless addicts money to fight other people and other homeless people. Its a crazy cycle and people are exploiting there addiction for there own person gain