This is already what some isps and networks are doing to identify and lock down P2P usage. The same techniques could easily be used to hunt down virus infected computers.

That’s just my prediction – that in the future it will be the isps that will be using antivirus methods. There are just too many pc novices out there posing as easy targets to infect. Maybe instead of obsessing with adherence to the DMCA, the isps could be looking out for us. Just like when your credit card company might approach you to ask if all those cash advances made in Nigeria yesterday are really yours. ISPs could certainly notice if a computer suddenly starts maxing out its bandwidth sending email, scanning addresses, or pinging servers, or doing other erratic behavior that often signals a virus infection.

However – the victory, while easy, may be short. The next generation viruses just might apply a lesson learned from P2P and start using randomized ports, encryption and/or spoofed addresses as an evasive tactic.