I wish various sites were more supportive of this. Back in the day, Yahoo! groups supported multiple identities very comfortably, so you could be "yourself" in professional forums and "be" yourself elsewhere. I don't know about anymore since I haven't used them in years. But most other sites that support pseudonyms mostly still work hard to make sure you only have one, which does little to curtail the possible abuses thereof while making it painful to do so for good reasons.