The IBM vs SCO tactic.
Don't just win. Invalidate their patents. Bankrupt the company. Destroy all their claims. Get their copyrights invalidated. Chase the lawyers.
Sure, it cost IBM 10 times as much as it could have, but you can be sure that nobody else is going to try that tactic (though SCO are still going, somehow... but at this point there's nothing left and everything they do is costing the lawyers money because of their earlier fixed-price deal).