Yeah I'm in one of the more controversial fandoms which does have some horrible behaviour like that (I stick to "nice" Brony sites though, ones with rules on civility and such, not very unlike this place!) and even I wouldn't touch the S:U one with a bargepole. Besides, one's enough.
Any fandom heavily weighted on Tumblr is one I'd tend to avoid. And that's not a political thing (I'm very left leaning) more a behavioural one.