He went into the classic paranoid mod mode, banning everyone who commented on certain threads - and in many cases muting them as well. It happens fairly often around here. The process seems to be:

1. Newish mod decides they are God, here to punish those who are heretical in Their eyes. They shall hereby be referred to as The Mod.
2. Innocent users have their posts taken down.
3. Those users complain. Brief conversation takes place in the sub about what's happening.
4. The Mod attempts to defend their actions to the sub. But since their actions are indefensible, the vast majority (in this case, EVERYONE) disagrees with The Mod.
5. The Mod's Wrath is incurred. Bans and deletions come more quickly.
6. Protest from the users increases The Mod's divine wrath. The rate of bans and deletions escalates. Preemptive muting is employed, as is banning on the basis of posts and comments outside of the sub in question.
7. Around this time one or more alternative subs are created by some of the newly-banned. Some members move there to talk about what's going on. This offends The Mod's sense of propriety, since to question Their Holy Will in a place They cannot control is sheer blasphemy.
8. People complain to Reddit, and The Mod starts worrying about getting negative attention from the admins. Like a cat covering up their scat, They start hiding or deleting any conversations that They feel might make Them look bad. In this case, that includes all the batshit-crazy stuff in their personal ranting sub.
9. Here we fork. Either Reddit and/or the owner of the sub does nothing, in which case the more aware segment of the sub users leave for the new alternative sub. We now have two separate communities where once there was one, to the detriment of both. The original sub either eventually dies off, or just dwindles and becomes irrelevant to most people.
   OR,
   Either Reddit or the sub owner comes in and finds the sub in flames. They take hasty action to eliminate The Mod, and hope that the sub will recover with minimal damage. The Mod crawls off to lick Their wounds and plot a comeback, some day.
10. Or - maybe - The Mod comes to their senses. Can't say I've ever seen that happen before, but I suppose there could always be a first time!