Well, you're not completely wrong but there are additional tests for search http://blog.constitutioncenter.org/2013/02/does-a-constituti...

> Searches within the 100-mile extended border zone, and outside of the immediate border-stop location, must meet three criteria: a person must have recently crossed a border; an agent should know that the object of a search hasn’t changed; and that “reasonable suspicion” of a criminal activity must exist, says the CRS