This reminded me of a problem with internationalised domain names, I think there's a Russian character that is pretty much indistinguishable from a lower case Latin "o" but it's not the same, it has it's own codepoint in unicode etc. The problem then is that someone can register perlmonks.org using the Russion "o" and people will be confused, scammed etc.

Veering off topic...

I decided to see if PM was vulnerable to this and tried to create an account with a name of "你好“ (chinese for hello). It seemed to go alright (no error messages). However, the name didn't appear as Chinese characters, it appeared as &xxx;&xxx; so it seems PM doesn't correctly handle general utf characters in usernames (which may be a feature, rather than a bug). Also, I don't seem to have received an email about the account yet either.