I'm not even sure to what level this has happened. But a certain recent President polarises/attracts polarising to a shocking degree.
Directly or indirectly. A wiki I'm a regular editor for had an edit yesterday that Obama was President for zero days, because he never even produced a valid birth certificate (a statement that's provably wrong/a vicious smear/trolling/whatever). The signs, at least to me, are that the edit (quickly reverted) came from someone who put Holocaust Denial (mis)information in. Same kind of fool/idiot/provocateur, definitely.
Call me jaded, but I've seen (and can see) places dragged into a terrible descent. Yay, even unto the mighty Twitter...
And my age/experience makes me arguably cautious, just because I've seen it/been there. Some Usenet groups survived The Eternal September better than others, and not all were pristine even beforehand. Even in one of my past jobs, in part I had to assess various corporate threats to my company, and prepare reactions (everything that seemed possible to attack its IT systems, from natural disasters to industry espionage) and reputational harm was one of the aspects to consider. After I left that position, a failure somewhere in the processes happened that really hit the company (I did not prod and pry, ex-colleagues were ex-colleagues so I left well enough alone, but the public bits were very much in the news) and I could only hope my own contributions to the policy concerned was sufficient/followed/in effect at that time, though the failure was not strictly an IT one. Perhaps something better. But I'm cautious and protective about such things (not that I always necessarily practice what I preach!) so I'm definitely sympathetic towards avoiding obvious issues that are obvious.
That's all I'm trying to say. And I can't see any problem with deciding that this particular rule (if it 8s one) is sensible. How it's applied (strong words at an appropriate moment, a weighted "three-strikes" system, clearly publishing a guide (but not an instruction manual!) to what is unacceptable) is another thing. And "no My Little Pony" could be considered reasonable, should those in charge so wish, as long as it doesn't pop up as part of an apparently entirely arbitrary judgement system. But I didn't mean to divert the conversation with this. It's beyond my control/experience so I'm just expanding on my considered reaction to the original comment. YMMV.