Abandoned games

Does anyone find it offensive (as I do) when players abandon games, rather than playing them out or resigning? Today I had an opponent who hung a piece on move 7, and then apparently walked away, leaving me to watch his clock run down for 11 minutes. Then a second player just did the same thing after 9 moves and a mildly unfavorable position; I watched his clock run down for 10 minutes. This is rude! If you're giving up on a game, then resign so your opponent can move on.

Anyone have ideas on how to prevent this? I'd like to at least be able to put both players on a "do not play again" list.

Try this and this.

those people exist. It doesn't help to put it up on the forum

I have had some abandoned games due to being disconnected. 

That may be true (the disconnect), although it seems to happen much more often right after my opponent has made a mistake.