This is an attack for pwning people who ship drugs and use Tor , not an attack for finding who is going to SR. Tor does a fairly decent job of keeping them from knowing that you are going to SR. It does nothing to hide the fact that you use Tor, unless you use bridges. The attacker already knows that vendors here use Tor. They can find roughly where they are geolocated by placing orders from them. Then they can say "Well, we know this vendor uses Tor and ships from this location. There are two Tor users in this area. One of them is probably the vendor". Now of course you can say so what using Tor isn't illegal, but this is where the distinction between evidence and intelligence comes into play. They will not use the intelligence in court, but they will use it to (legally) pull over the two Tor users (when they are speeding)...or they will (legally) pay extra special attention to the mail going to those two people. You hide with a crowd. Tor assumes that your initial crowd is "everyone in the world who uses Tor". When you make your initial crowd "Everyone in this rough geolocation who uses Tor" you are seriously fucking hurting your anonymity. Tor doesn't take into consideration the mail part of our threat model, as far as Tor is concerned the attacker doesn't know your rough geolocation. this is why it is important to actually know about security....if you don't know the limitations of your tools you will end up fuxx0red but this also assumes the feds know what they are doing, and it really seems to me like they don't although I know some government people do, its really hard for me to wrap my mind around how they are both completely incompetent and ultra leet simultaneously but it tends to be true. Even within the federal police agencies themselves , disregarding military and intelligence.