Here's some published research on the topic: http://hal.inria.fr/docs/00/47/15/56/PDF/TorBT.pdf And if you don't trust that link, it's posted on the official Tor blog: https://blog.torproject.org/blog/bittorrent-over-tor-isnt-good-idea I think you could run wireshark in a VM to show the leakage. One of the problems is the bittorrent client bypassing the proxy settings to connect to the tracker, because that is usually done via UDP while Tor only carries TCP streams.