Ehh, not completely sure immediately stripping their powers that quickly is a great idea; some of them could have had even higher leveled adventures steal from them multiple times and nobody caring about them to the point they decided the world was ok with it and merely a fact of life; a bit more questioning, etc, would have been better. Could have also technically have had a robinhood type person who saw someone using another as slave labour and stole from them to give to the actual worker. Sure, all those cases are unlikely, and they likely were all trash, but still feels hasty, and odd to the outside world that a single classroom would be targeted too; better to start in the dungeon on anyone he witnesses doing so.