Earlier quoted context omitted.
I wouldn't for a second bet on it. A hidden service has exactly the same issue as traffic that exits the network. The topography looks like this. httpd > tor node > tor node > tor node > rendezvous point With enough monitoring, the location of the web server (or other hidden service) can just be found out by bombing the hidden service with traffic and seeing what end point lights up with traffic. With fine enough mon…
According to tor metrics only 17% of tor endpoints [1] and a similar percentage of relays [2] are in the USA. The kind of monitoring you propose would require a much higher portion of them to be under NSA control. [1] https://metrics.torproject.org/users.html [2] https://metrics.torproject.org/network.html?graph=relaycount...
The bigger protection is the ease with which the NSA can mount this attack on TOR. I have no doubt that they could do it, however I do question if they can do it on a massive scale.