I think this is one of the biggest concerns for Reddit going forward. Fighting bots can be approached systematically and with relatively decent results. Fighting coordinated groups with an agenda and voting brigades is a much harder beast.
The SRS "fempire" is probably the scariest case study in all of this.
Oh, that's funny. Shit Reddit Says is a sub-reddit that calls out offensive comments on Reddit. They've been called the PC Police and the like, and they appropriated "fempire" after people got sensitive about being called out for sexist comments. The rules say not to downvote the linked comments, but people think they do, or that they upvote stupidity just so they can highlight it. So research was done [1], and no evidence of that sort of misbehavior was found.
On the contrary, SRS is one of the most innovative uses of a subreddit since Reddit's inception. Think back to the days of forums, LiveJournals, mailing lists, IRC, etc. Whenever an issue of discrimination arose, it was always derailed one way or another. Between vocal opponents, concern trolls, and "explain to me how this offends you"-types, it was impossible for someone who experienced discrimination to find a safe space to legitimize their experience.
With SRS, instead of allowing any kind of discourse related to the validity of a claim, every participating member is required to just accept the claim as valid. There is no driving force to change Reddit, and there is no activism involved. It's simply a safe space for people who are offended to express themselves in an environment that won't be questioned, especially when Reddit is known for having a hive mentality.
No offense, the warm and fuzzies are great; but this is the anti-thesis of intelligent and productive discourse.
I wouldn't mind at all if they just wanted to create a safe place for these things to be voiced, but they threaten the integrity of the entire community with the current choice of actions.
The SRS "fempire" is probably the scariest case study in all of this.