I don't know shit about drug laws but couldn't they at least do something with this? Just to at least have any kind of punishment.
Even with that, depending on how the local laws are written you couldn't get them for anything, especially if they don't actually have drugs or drug paraphernalia on their person.
(Plus if you're for drug decriminalization I don't think wishing for them to be charged makes much sense. Two wrongs don't make a right and all.)