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Getting suspended.
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Name change.
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Return to anonymity.
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Role-playing.
I think that covers all the bases.
I've never heard of any other forum that has this problem
Reddit for one. Since it's pretty common for people to creep your post history and also witch-hunt those who go against the circle-jerk. I create new accounts all the time to stay anonymous. And a lot of people have throw-aways for discussing sensitive topics since reddit is so popular it's common to be recognized and your identity linked with your posts.