Fourth Straight Federal Court Rules Publicly Shared P2P Data Has No Privacy Rights
If you chose to open your data to the public, it is "open and obvious" to law enforcement
The investigators used a piece of software by TLO plc dubbed the Child Protection System (CPS), which searches public torrent hosting sites for terms that might relate to child pornography. Once a positive hit has been verified the tool investigates the site where the torrent was posted (as most major torrent sites like The Pirate Bay remove such links, child pornography torrents are typically hosted by individuals actively involved in criminal child pornography) and records the "IP address, the files' hash values, the actual file names, date and time of response, and other computer detail" according to a blog by Sophos plc.
IV. The Devil is in the Details -- So Tread Lightly