Given that Silk Road was just shut down, an article was published stating that:
Tor Can't Always Keep You Safe; Just Ask Silk Road ... careful traffic monitoring and a little math you can figure out who connects to what on Tor. - Reference
Another article - nearly a month older, claims something similar:
Not Even Tor Is Safe From The NSA’s Prying Eyes ... The problem boils down to this – around 90% of Tor users are still using older software which can be hacked. The good news is that the latest version of Tor, version 2.4, isn’t believed to be ‘crackable’ by the NSA, as it uses something called elliptical curve Diffie-Hellman ciphers that are thought to be beyond its capabilities at the moment. - Reference
Additionally, another states:
Tor still helps here: you can target individuals with browser exploits, but if you attack too many users, somebody's going to notice. So even if the NSA aims to surveil everyone, everywhere, they have to be a lot more selective about which Tor users they spy on. - Reference
- Are the articles referenced above true in their claims?
What I can gather from this is that safety boils down to the habits of a user themselves. Are they using https, what information are they sharing online, what associations are being made.. etc. Related.Related.
Assuming all safety precautions are taken into consideration by the user, how safe are Tor users - regarding anonymity?
Does Tor still present a threat to the NSA?