How do you fellas want blizzard to ban HIM directly?
Through his DNA absorbed through the keyboard and teleported to blizz HQ?
Or have a crack team of spies monitoring his physical location for a new diablo 3 account?
The biggest penalty a gaming company can inflict is ban your account.
They can NOT ban your IP or your PCs MAC, and even that kind of a ban can be circumvented with various software/hardware.
The only greater penalty could have been banning ALL of blizzard games on that account - if he even had other games on that account.
But i don't think blizzard bans you from ALL of their games if you cheat in one of them.
They do have a lot of his personal information. You can't have an account without putting in your name, addresses (physical and email), and CC info (if you purchase through b.net). It wouldn't be hard to implement something that prevents you from associating a new license key to an existing account when they try to get around the ban. If they try to create a new account, then you can also implement a check to see if any of the user's information is tied to a banned service/account and deny the creation of the account.
That recommendation cost a good chunk of change though. I would suggest that they get better at banning botters/exploiters more quickly, frequently, and more reliably. A botter may not care about being banned once or twice, but if you start banning them weekly/monthly, then those software charges start to add up more quickly. Having to pay an additional $70/year for an annual ban is one thing, but it would be another if you banned bi-weekly ($1,820). At that point, if the botter/exploiter wants to pay for that much for the game, then let them. Their "stupid tax" can help pay for additional feature development in a game that I play in a legit manner.
...well, used to play before my system died. RIP. Still feeling the sting from that one...