[ergothus]

> This ruse solved my support team's problem.

Having places where I don't recall if I have an account, and if I do, which of my email accounts it was registered to - this solution would actually make me happy. I recall running into it once or twice in the wild and was always just as happy to get the "we don't have an account with this email message" in either email or immediate feedback. That said, I agree with the poster that sees the actual security of hiding usernames as marginal at best, outside of sites where the mere presence of a user is indicative. ("Johnny, why do you have an account on "ILikeLeadingCommas.com"?!")