I don't find AFKs very often when I'm searching for games, though people who bugger off for a round or two are a regular occurrence. It gets really annoying, an especially late game where the rounds really count, and they just piss off to go and do other things. Really annoying, but if they're AFK long enough, the timeout for an hour, a week etc should be enough to get them to start playing instead of just going AFK
"It never hurts to keep looking for sunshine" - A. A. Milne