How about BitTorrent, then? The creator of that intented that his program be used to distribute large files very quickly, and it has been used like that. RedHat distributed it's latest edition over BitTorrent, and got copies of it's program out to users much faster than when everyone had to download from FTP sites. Other sites have borrowed from the BT concept, because it helps save bandwidth, as well as get files out faster.
However, BT is also being used to distribute copyrighted games, movies, music, and more. Should Bram Cohen be sued because he created a protocol that is being used illegally?