The National Security Agency broke the TOR network and exposed thousands of dissidents to arrest from repressive regimes because terrorists and criminals use it, too.

Director of National Intelligence James Clapper said the NSA attacked The Onion Router, or Tor. Writing in his bog, Clapper said NSA’s was interested in tools used to facilitate anonymous online communication. But these are the tools adversaries use to communicate and coordinate attacks against the United States and its allies, he said.

Tor was exactly the sort of traffic that the NSA is hoping to capture and analyse. New attention has come to Tor and its users in part because of the arrest Wednesday by the FBI of the alleged operator of Silk Road, an online marketplace for the sale and distribution of illicit drugs that existed in the so-called Dark Web, reachable only by a Tor-enabled browser.