If there's one thing that irritates me around here, it's that the moderators have a hair trigger finger when it comes to anything even remotely controversial. Witness this perfectly polite conversation on the subject of modern military strengths and strategy. See Mr. Moderator. See Mr. Moderator come in and have a coronary over the polite discussion.
Some reasonable limitations are of course neccessary for maintaining a subject-oriented forum environment, but when you take it too far it can play havoc with the sense of community, as well as reasonable discourse.