They can censor anyone they want to, because it's their site. The only serious quibble I have about this is that there seems to be two sets of rules... one set for a small number of people, and another set for the rest of us, and neither of them is the one posted in the FAQ. The actual rules (if you're one of the people covered by the second set of rules) you don't find out about until after you've already broken one of them. If you're one of the people covered by the first set of rules, the only rules seem to relate to how others are allowed to behave toward you, but there are no rules about how you may behave toward others. But it's their site, and if they want to have two sets of rules and keep them secret, that's their right.