and security on pages is useless if you are logged in.

We're already talking the least of security problems (IE the device being physically confiscated).

In ross's case which hurt him more do you think, the fact that his system probably had logs of what he installed... or the fact that it was taken while he was logged in as administrator to the silk road? and it supposedly contained a journal... not system logs, but activities that he specifically wrote out detailing his daily activities.

The point again is someone gaining physical access to the computer itself, while you are literally in the process of doing things that you don't want known about, what you are currently working on is 100x more valuable to the thief, feds or whatever, than any of the low level stuff that the logs are likely to be recording.

Ross was foolish to be running the largest black market in the world from a public library. They make magnetic kill switches for that sort of thing. No amount of security is impervious to bad decisions.