if what you're thinking is..

if we make it so that marijuana users have to stay inside, then they'll stop having fun and stop doing it.

...then that's completely wrong, and based on a total misunderstanding of what marijuana is all about.

that might work for cocaine, or meth. but, marijuana users hate people, anyways, and would rather smoke alone, and pout by themselves - that's why they pick the stone, rather than the high.

what you will end up with is chronic, paranoid marijuana users stuck on disability for life.

but, if you encourage them to come outside and meet people and be more social, you might even help them break the habit a little.