I was thinking the same thing - a nontrivial effort has clearly been spent on implementing this, and it certainly would not be well-received by most if not all of its customers.
Being sued by Hollywood for a billion dollars and passing those costs on to their customers wouldn't be well-received either.
Is there a reason to believe such case would have a chance of succeeding? I thought DMCA clearly protects the ISP as long as they forward the complaints to the offending customer?