I was introduced to it by a friend of mine, downloaded the
Tor Browser (looks/feels identical to Firefox). Government software? heh.
The browser is still available and useable...the internet would be a much more anonymous place if everyone used it. Google would throw their toys out of the pram.
Obviously its hard to outwit the FBI/NSA/CIA/DoD/other alphabet letters, there's probably some scandal waiting to be leaked about the Silk Road having some government involvement (much like government planes getting caught smuggling class A drugs from Central/South America).
Linked to Silk Road and that kind of thing is Bitcoins. Bitcoins will fail because people's currency can supposedly be hacked and therefore its not safe to use. But if you really think about the normal banking system its no different to Bitcoins in the sense that people have/will always try to steal both physically and electronically.