There has to be an option between locking people up if they're trying to destroy their lives and standing around doing nothing - if not actively helping them.

There has to be an option between locking people up if they're trying to destroy their lives and standing around doing nothing - if not actively helping them. The people wanting to use drugs would view "punished" as anything that gets in the way of them and their drug of choice. Saying it harms no one is to say that the person using isn't being harmed. I have (though probably used to have more) libertarian sympathies but it seems like that falls down in a large number of hard cases. I don't want to run other people's lives any more then I want someone else to run mine but there's an extreme version of the libertarian argument that equates any help with control.