[jhugo]

If the human customer service provides an off-ramp from being banned, then the fraudsters will use that too. So the question still boils down to the exact same thing in the end: how do you reliably tell the difference between the fraudsters and the legitimate customers?

[protomyth]

Don't know, not my area, but like every other business in the US that cost should be born by the business not the consumer. Don't push large groups of people to the thin ice if you don't want laws passed.