What whack-a-mole? Just automate it so if it gets double-spent, you revoke the key. If you really feel like it, cancel the account if they keep doing it, but I'

What whack-a-mole? Just automate it so if it gets double-spent, you revoke the key. If you really feel like it, cancel the account if they keep doing it, but I'm not sure you even need to bother. What have you lost? The bandwidth to download the game?