I would like to have something like a hash file system. So I clung to a closed tracker, which purpose is not the distribution of content, and distribution of files that I have shared with other users. To drop system I had the opportunity to quickly get back your music, movies, and disk images. I have backup copies only unique data, which is not much.
This tracker would not have violated the law because no one would on this site have not seen any files, and the client would have just clung to, received from account a list of files with hashes and rocked to the other users. Although I am not a lawyer, but in my opinion it's not really file sharing.