Contains personal information that could be used to track, identify, contact or impersonate someone (e.g. name, address, phone number, email, or credit card details).
For each request sent, the tracker returns random peers at a limited number. For instance, if there are 1000 peers in the swarm and the tracker sends only 20 peers for each request, there must be at least 50 requests sent to know every peer in the swarm
In theory, someone with enough technical skills could create a script that tracks which IP is downloading which video. In practice, this is much more difficult because: