I guess this question fits here...

We just noticed that if you send a PM to a username that doesn't exist (because of a typo), it will report that that user is over their private topic limit instead of indicating that the username doesn't exist.

If this isn't a bug, could someone explain the rationale of the design decision to me? It doesn't make sense to me - even from a security perspective. We'd really prefer that it replies with a "this user doesn't exist" type of message, and I'm not seeing a way to easily do that.

TIA.