It barely sounds like these people are exercising any free-will at all. Humans can be conditioned into doing all manner of things that aren't good for us, but it isn't right to just stand back and go "welp, free-will says I can't interfere so I wash my hands of the whole thing and let them go on wrecking their lives."
We live in a community, and with that comes the responsibility to help those around us (friend, stranger and enemy alike) realize what's good for them and what's not. Banning things left and right is not the answer, but neither is standing back and doing nothing. People have the right to throw their lives away, but we just have to make sure they know they're doing it.