Honestly, a lot of people do drugs because their life is terrible and they just want some release; society would do better to help people, like in this case, to make sure the children have food and shelter, than to punish doing drugs. Countries that have made all drugs legal, even the really dangerous ones, generally sees less harm from them because then people who are using them know they can go get help from a doctor if something goes wrong without worrying about being arrested, or they can go and get clean needles from a doctor, that kind of thing. But definitely cannabis (marijuana) should be legal - it's less dangerous than smoking tobacco, even if you do it just for fun, and tobacco is legal, plus the health benefits. It can help other problems too, like pain or people who are on cancer treatment and have no appetite use it to have an appetite again, or treating seizures.
RE: What should society stop first !