I've never joined a rule with stupid rules, even though I have Posted on WrongPlanet for two years. Never had a problem with the moderators there except for the lack of moving threads around to proper forums which kind of bothered me.
Though I am reminded of Nexopia where even images of fake blood could get you banned. Since there was a very active Goth, Industrial, Metal, Punk, and BDSM forums within that place, you could not even post images from the local zombie walks that nearly half the people on the site took part in. So it was really strange and a lot of people got banned for that rule - which I think took a fair bit of wind out of its sails. The real kicker was when Facebook took a huge chunk of the market. A lot of teenagers still use it but not like they used to.
Ones that I know of that has really wonky forum rules would be SomethingAwful. Textbook case and they make it a point to be like that.