Interesting idea. It could very well work, but it could also crash and burn.

What troubles me is that you're asking these high-bandwidth machines to essentially act as shields for the rest of the gnutella network. The policing you're refering to doesn't even need to occur to bring the network down. Simply pay your employees a few bucks an hour to pull stuff down on gnutella through these proxies. Wham. You now have a situation where the proxy machines either have to ban every single person who's using their machine to share copyrighted data, or be disconnected by their isp through the typical complaint-and-ban process.

Certainly, it's quite easy to determine who your proxy is, even if it's not apparent in the gnutella interface itself. A simple netstat will be enough to determine that much. The encryption isn't an issue because the policing machines *are* the machines recieving the public key. And now you've made the network more centralized, with a handfull of high-bandwidth proxies to go after instead of thousands of users. Even if the proxy machines aren't sharing any files themselves, if they aid in the distribution of copyrighted material, they can be shut down if they persist in that behavior.

So, yeah, I guess you can provide anonymity for a good number of users, but only by putting a smaller, and therefore more vulnerable, group of users at greater risk. Under those conditions, I wonder who would be willing to act as a proxy in the first place.