This has already been weaponized by subs like /r/AgainstHateSubs and other vigilante-like subs. Their tactics usually involve posting in those subreddits from sockpuppet accounts, using hateful or threatening messages. The few times the targeted subs mods aren't on the ball, they mass report the post for hate speech to try and get the sub banned, or the mods banned then later request the subreddit for themselves, something of a trophy I guess. On rare instances, they reach out to their freelance journalist friends to write a hite piece.