Every torrent download is public: when you download a torrent, every peer in that swarm sees your IP address, what you're downloading, and when — and it's logged. AnyoneCanSeeWhatYou.download watches swarms live and shows what the public record says about any IP address.
Your public IP address is sent to the tracker and to every peer you connect with. Anyone in the swarm can see who is downloading.
Torrents have unique hashes and names. Observers can record exactly which files an IP address downloaded, and when.
Search for any IP address to see what activity is publicly associated with it.