Here’s something I did not know: The Fourth Amendment’s protection against unreasonable search and seizures does not apply at the border. More precisely, arbitrary searches at the border are not considered unreasonable. Thus, customs agents and the like do not need probable cause, much less a warrant, to search people entering the country.
Okay, maybe that makes sense. But the Department of Homeland Security claims that it can use its powers of suspicionless search, not only at the border, but within 100 miles of the border! The ACLU has prepared this handy map, showing where the government says it can search you without probable cause:
The Supreme Court will probably squash this eventually, but it’s an outrage that that’s necessary.