“You don’t know for sure how they will get the money if not by your donation”
You mean whether they will steal, rob or prostitute themselves; any other options for a drug addict?
So what would you say to the mother who collects money for her daughter’s addiction so that the daughter won’t have to sell herself?
The Rambam says that if a fellow is used to the finer things in life and becomes poor, you are m’chuyiv to support him in the standard of his lifestyle; fine wines, steaks, Brooks Brothers and all.