In case it hadn’t crossed your mind, your Google Webmaster Tools account (and most likely other Google services) are a permanent record of your activity.
Delete a site on Webmaster Tools and it’s not really gone. Don’t believe me? Try attaching your Google Account to show stats for a site on somewhere like Digital Point and you’ll magically see site names that you deleted long ago.
What do you think happens when you keep doing dodgy stuff and all your accounts are connected on Google Webmaster Tools (or Analytics)?
I wonder how long it will be before there is a market for Google Accounts in “good standing”. I’m certainly not the only person that’s noticed launching almost identical sites on different accounts has its differences.