What's the process of banning a subreddit? Is it based purely on number of reports, or is there actual research done to see if a sub is actively promoting brigading?

It's fairly obvious that /r/fatpeoplehate was a controversial sub and there was plenty of hate for it that would garner a lot of reports. Being a fairly active subscriber, I never saw any brigading of other subs and the mods were good about shutting down links to other parts of Reddit. People that posted links to other sections of Reddit were actively removed or even banned.

What's to stop a sub like SRS from having it's members mass report the sub and say that things like brigading aren't happening in order to get it banned? What's to stop people who disagree with the sub from creating an account, subscribing, and going into other subs trying to get it banned?

My main question is: do you ban a subreddit based on subreddit behavior, or individual user behavior?

It's impossible to control every single user of a sub, especially one where the members have such strong opinions. There should be nothing against a FPH subscriber going into another sub alone and voicing their opinions. Since there are a lot of FPH members, more than one of them might show up in any given thread. This doesn't constitute brigading; this is multiple individuals with similar ideals participating on an active web board.

If you're going to ban subreddits and say it's due to the actions of the subreddit, I feel you should provide proof that these actions against the Reddit TOS are occuring.