A few months back, the TSA and Homeland Security ruled that security agents could confiscate and search the laptop of an American citizen traveling into or out off the country, without a warrant.
When I heard about this, I immediately encrypted my laptop with Truecrypt, figuring that they could not make me divulge the password, based on my 5th Amendment rights.
A judge has just ruled that if you encrypt your laptops hard drive, the government cannot send a subpoena forcing you to give up your password. This means that you should be safe from searching, since a laptop encrypted with Truecrypt AES 256 and a strong, random password would take decades at minimum to break.
I would prefer it if the TSA got a warrant, as they are legally required to do, by the Constitution. But this seems to be the next best thing.
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