What about changing your BIOS to intercept keystrokes? Or hacking the hard drive firmware, so they would have the master key for your encrypted disk next time you cross the border? A lot more effective than any other software-based solution.

A few years ago we'd say this is all crazy conspiracy theory. Nowadays this this is just NSA's business as usual tactics [1].

[1] http://news.cnet.com/8301-1009_3-57616334-83/nsa-reportedly-...