Vanished opponents...what to do?

[Fubar]

When both my PC's went bang a few months back i used a friends PC to send an email to all my opponents and told them to claim a TC, but not everyone has another means of connecting to the internet so i usually keep old unfinished games in a folder just in case they should come back.
But i don't think there's anything wrong with claiming a victory, especially if you spent a lot of time on the game and feel cheated out of the win by someone who just lost interest in the game.