US customs has always had the authority to search through goods being brought into the United States, whether by a citizen or a visitor. I'm fairly certain every country reserves that right, and some probably exercise it even more frequently than the United States.
What is an evolving point of law is whether the right to search goods being brought into the United States includes the right to search through information contained on an electronic device, as opposed to merely searching the material nature of the electronic device, especially if the person to whom the electronic device belongs is a US citizen. There have been several somewhat recent court decisions that seem to be pushing back on the US customs claim that they have the authority to search the information as well as the physical device; it is unclear to me where the ball will fall with the final spin of the roulette wheel. It is difficult for the customs folks to claim that their search is necessary to prevent the introduction of illegal information into the US, or to claim that it is necessary in order to enforce US tax law or tariffs on the information, as far more information flows in (and out) of the US on data networks. In the case of a citizen, searching through that citizen's information (without a warrant) seems like an unwarranted invasion of privacy (pun intended), that murky right described (somewhat) in the 4th amendment to the US Constitution.
Biting the hand that feeds IT
