XF 1.3 Search for threads by guest?

[Gossamer]

Is there a way to search for threads that were posted by unregistered users? My forum periodically cleans out inactive accounts. We also move their application to an archive. We currently do this thread by thread, but I was wondering if there was a way we could just search a forum for all threads posted by a "guest", so we can more easily accomplish this.

 

[Paul B]

There is no way of doing that as the only member criterion is user name.