Traffic Analysis allows to reveal majority of users on Tor Network(openrev.org)
openrev.org
Traffic Analysis allows to reveal majority of users on Tor Network
http://www.openrev.org/paper/on-the-effectiveness-of-traffic-analysis-against-anonymity-networks-using-flow-records
It's an active attack, meaning it requires packet modification. Its been done to death, see stream watermarking, etc.
Show me an effective passive attack with a powerful but non-global adversary and I'll be impressed.