I believe reading that Ross Ulbrict's computer was completely encrypted and only accessible with a passphrase. The minute he logged out or closed his laptop's lide, the information was completely locked down.
IIRC, they were able to get his information by an elaborate scheme acted out by plainclothes police where they grabbed his PC while his computer was unlocked. Without looking it up, I think someone bumped into him and one officer took his laptop while another one on the other side grabbed his phone.
Two plain clothes FBI officers followed him into the Glen Park public library. A third, undercover, agent contacted Ross online and asked him to log into the silk road backend to fix something. The plainclothes engaged in a fake lover's tiff right behind Ross' chair, who then turned around to see what the commotion was. When he did so, the male officer pushed the laptop to the female officer, who took it and began extracting evidence. Ross stood up, and then was arrested without resistance. Evidence gathering happened in the library.
IIRC, they were able to get his information by an elaborate scheme acted out by plainclothes police where they grabbed his PC while his computer was unlocked. Without looking it up, I think someone bumped into him and one officer took his laptop while another one on the other side grabbed his phone.