Interesting.
In my point of view (in our law) it would be the same as forcing a murder suspect to lead the cops to the place where the victim's body is hidden.
No suspect may be forced to actively cooperate with the police anymore than giving ID. A suspect can be forced to submit to police actions, for example may be subdued so that a blood/DNA sample can be taken or restrained so that a bodily search can be conducted.
When I have to teach trainees, I loosely explain the concept of nemo tenetur (that's the Latin shortcut for the idea that noone has to incriminate oneself) by the following idea:
First, decide what kind of cooperation is required, if any: active or passive.
Passive cooperation means that the suspect is essentially required to "sit still" and let others do something (like having a doctor put a needle in his vein to take a blood sample). If there's a law allowing to take that kind of evidence, then forcing passive cooperation is ok.
Active cooperation on the other hand means that the suspect has to take action, he has to DO something. If evidence cannot be gained without active cooperation of the suspect, then forcing it ALWAYS violates his right not to incriminate himself.
That is why I don't think the comparison with a locked safe and its key is a good one:
If the suspect does NOT hand over the key, the safe can still be opened by force with the proper equipment. So there is actually only passive cooperation of the suspect required in that he doesn't hinder a technician to use a blowtorch or whatever to open the safe.
The difference with file encryption is, of course, a practical one: Passive cooperation won't help, unless you want to wait a few hundred years for the results of a brute force decryption attack. So, active cooperation is the ONLY way to get the evidence.
So a better comparison is indeed the idea of forcing a suspect to lead the police to the hidden body. Because digging over every square-inch of the country is practically impossible, so if the suspect doesn't lead the police, they can't find it.
As far as border guards DID see images before the laptop was shut down, that's certainly admissible evidence. They are witnesses and can be asked about details of what they saw. Whether that's enough for a conviction is for the court to decide.
I also disagree with the concept of "the govt already knows where the evidence is". Simply because it doesn't. The police knows filenames, but not what the files are. If I name a file "terrorist_attack_plan.doc" just because I can, that doesn't at all mean that it's truly a terrorist attack plan. And I don't have to justify how and why I name my files, either. Of course in the context with other evidence it may potentially make such a strong case that it may be enough circumstantial evidence to get to a conviction. (And if that starts to become likely, maybe I'm better off to open that file and let the court see that it's actually my laundry list.)
Anyway, once more, I am glad I don't live in the USA (though, in my job, it might actually be a good thing if I did).
