@Gone That's their angle - they use "special software" which they are not the developer for, and isolate the supposed IP's that uploaded even the smallest portion of one of the file peices. That's it. I don't know if the software can identify which bits and bytes are from each independant IP address or not.
Oh, I know what their angle is. I am simply saying that it isn't good enough as they have no way to prove that the IP they captured was making available a 100% complete and working version of the infringing material based on the extremely limited number of pieces they capture.
Just like they are using a "hacked" copy of torrent client for honeypot, a user can also find "hacked" torrent clients that lies about their uploads, share ratio, completion and other stats too.
Having only a few non-sequential random blocks of data in torrent is very much like a random patch of data in a CD that is partially destroyed by a microwave oven. Not until you have recovered enough of the directory structures, file header etc, you can't even make sense out of the raw data.