Youhavedownloaded.com can link legal and illegal downloading activity from a number of file sharing sites to a database pf 52 million online identities. Users can search the database by IP address, file name or by the name of a torrent (download file) It can then inform users what IP addresses are associated with what downloads, or if anything has been downloaded from a particular IP address. The service is just a proof-of-concept, but could create headaches for public figures and others who have been pirating content online.
Source: https://threatpost.com/creator-new-site-claims-out-online-pirates-among-us-121211/75989/