anonymous P2P, dangers of Tor?

The Tor network is often discussed as a safe way to surf the Internet anonymously. However, Tor has certain dangers, in some (very few) situations, using Tor is more dangerous than not using it. Also discussed in my techblog article, does the Bittorrent client uTorrent work with Tor? It worked anonymously only under very special circumstances (a firewall jamming direct connections). However, using Tor and P2P is usually able to break through P2P traffic choking by a Firewall or an Internet provider.
NOTE: downloading content via P2P can be perfectly legal, that's why statements in the techblog article are not meant to encourage downloading illegal (copyright protected) content. The probability to be tracked by anti-P2P companies is almost 100% nowadays