It sounds like he's going down the road of Trusted Computing, which would be pretty effective at keeping malicious software off of the machine, but is generally a pain to keep working.<p>It doesn't work against hardware mods like keyloggers either, although most hardware mods aren't something you can shove into a laptop in 5 minutes while it's inside the X-Ray machine.<p>But really if you set a BIOS password and encrypt your hard drives you've already set the bar pretty high for someone to own your machine in a reasonable timeframe. If the authorities insist they keep your laptop overnight then you should probably just burn it, but for short stops you've pretty much eliminated most of their options, especially with modern laptops that are difficult to service in the first place.