In our case we were educating and protecting our customers. It's usually bad policy to carry out punitive punishment on your customers. :)
In fact, the worst offenders were actually rewarded. They were the only ones who had two factor auth for their eBay accounts. Back then we didn't have soft tokens -- the only way to do 2 factor was to get a physical RSA token, which cost about $10 at the time. So only the "best" customers were worth the cost.