One of my friend got a notice from Optimum Online for downloading Adobe Photoshop sometime last year. So I think yes, there is marginal policing that is going on form ISPs already.

I think this probably is a better solution than RIAA going after people and suing them for absurd amounts of money. While I don't agree on policing on principle, this could be the least acceptable alternative.

Though, I think this is also a good time maybe for VPN services to mushroom around other parts of the world that could be used from USA? (Though, technically you are more easily traceable when using a VPN, since you have signed up with some identifiable information.)