Not exactly new
Borders are one of the places that the 4th Amendment does not protect individuals; as well as things such as searching persons when they are arrested & exigent circumstances, & plain view.
The standard for when the 4th Amendment applies is if there is an expectation of the right to privacy. (And there is no right to privacy in the Constitution, though it implied with the narrowly defined rights in the Bill of Rights. The concept came from later Supreme Court Justice Louis Brandeis and his 1890 article in the Harvard Law Review) At international borders, there is no expected right of privacy.
If you don’t like it, work to change the law, but it isn’t new.
This has nothing to do with an “implied” right to “privacy” — it’s a gross violation of the explicitly stated right to be secure in one’s person, papers, and effects.