That's pretty funny! I've had lots of random friend requests, but no one ever has ever said anything to me when I've said no...which is my usual response.
I used to do the accept then delete when they signed off, but I felt bad about that so I don't do it anymore. Nowadays I'm just very selective on who I friend, and clean up my friends list from time to time based on who I haven't seen online in a long time, who I haven't played with in a long time, who I don't remember (lots of those [darn similar names...] LoL), and who has annoyed me by TPing to me without asking.
Really, there are only a few people I would actually consider game
friends on my list.