[imbur]

It depends on the reasonableness of the search. Physically inspecting bags to prevent agricultural products and weapons is both more effective at protecting the country, and less invasive into the personal lives of the travelers. Searching your phone is not just what you are carrying with you, but your entire connected life. Because the CBP is doing so few of these searches already there is little reason that they cannot get a warrant in cases where there is a real reason further search is needed.