So, as long as them searching your laptop would cause exceptional damage to the property, they may not be able to search it?
If I do not have to divulge my PGP password AND I have some sort of utility on my computer that erases my hard drive on 5 failed login attempts, I would reasonably think that would be considered exceptional damage. (Think Iron Key -- though I do not know of an OS/boot based utility that may do that)
Excerpt from Wikipedia Border Search Exception:
"Instead, the court ruled that searches of electronic materials are legally equivalent to searches of property. As such, Customs' authority to search electronic materials at the border are limited in only two ways: (1) the search may not cause exceptional damage to the property; and (2) the search may not be conducted in "a particularly offensive manner.""