Dang it! The only bugs I've found recently are in my kitchen! (All squashed, of course!)
I never did get their thought process behind the t-shirts... though I might have left the "r" out in conversation with other brothers of the web. :)
Doing things on the cheap, or thinking folks will be happy with a t-shirt for discovering and reporting (instead of taking advantage of) serious security, has been an amazement.