Reading the Krebs story on this same topic (http://krebsonsecurity.com/2014/09/dread-pirate-sunk-by-leaky-captcha/ http://krebsonsecurity.com/2014/09/dread-pira

Reading the Krebs story on this same topic (http://krebsonsecurity.com/2014/09/dread-pirate-sunk-by-leaky-captcha/ http://krebsonsecurity.com/2014/09/dread-pirate-sunk-by-leak...), it occurs to me that FBI may not have needed to try to authenticate at all. Basically all the analyst said he did was to load the SR website far enough until the captcha popped up, and notice in the wireshark (or equivalent) logs that a non-Tor IP address was reached from the SR website. If the analyst tooled around on the website after that, then even if the court were to call foul on that subsequent access, the public IP address wasn't derived from tooling around so it (and the evidence derived from that) wouldn't be at risk either.