system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5:How do they catch people torrenting?

Can they catch people streaming copyrighted content?
gpt
Let's start with how the torrenting works.

By seeding a torrent, you let a tracker or more than a tracker know that you are sharing the contents of that torrent. Then, you can upload the link to that torrent on tracker sites such as thepiratebay (Which is basically just a massive list) so that people can download FROM you and share it themselves.

This is basically peer to peer sharing and there is one receiving side and one sending side. The magic is there are tracking sites that let people know people are sharing some content and clients that prevent people from doing bad things like lying about what they upload. There is no third side and that's where the problem begins.

The company who is persuaded that piracy is bad can upload its own files to see if people will download them. If people do so without a VPN, that's bad news for them because the uploading side knows that someone with their IP is downloading their leally protected content from them. Which means they can bust you.

So, use a VPN if you want to be safe or don't download "hot" torrents like EA's games. Stuff with fewer seeders usually turn out to be safer (music, movies etc.)