neutral and legal

Chairman Julius Genachowski pledges administration support for network neutrality:

This principle will not prevent broadband providers from reasonably managing their networks. During periods of network congestion, for example, it may be appropriate for providers to ensure that very heavy users do not crowd out everyone else. And this principle will not constrain efforts to ensure a safe, secure, and spam-free Internet experience, or to enforce the law. It is vital that illegal conduct be curtailed on the Internet. As I said in my Senate confirmation hearing, open Internet principles apply only to lawful content, services and applications — not to activities like unlawful distribution of copyrighted works, which has serious economic consequences. The enforcement of copyright and other laws and the obligations of network openness can and must co-exist.

Question: if you were an engineer tasked with curtailing unauthorized distribution at the network layer where neutrality applies, how would you do it? What would your algorithm be?