[jiggawatts]

> p2p sheriff

My trick back in those days was to make an inverted filter. Instead of trying to blacklist the sheriffs, I white-listed peers.

Back then I was with an ISP that had an unusually large number of "peering" connections that were unmetered -- they wouldn't count towards the monthly download quota.

I tracked down the IP subnets for each peering company and then wrote a little program that would block everything except peered network ranges. This worked surprisingly well! Despite filtering out 95% of the Internet, my connections were short-range and high bandwidth, so I actually had slightly better download speeds -- and no more scary emails.

I did feel bad about one thing though: I couldn't figure out how to invert the subnet list efficiently, so I made a 4-billion entry bit vector (just 512MB!), flipped the desired ranges, and then exported from that.

I can feel my CompSci University professors shaking heir heads in shame.