That seems to be the news from this piece over at Vice:
Hundreds of thousands of travelers cross US borders every day. And none of them—save the precious few with diplomatic immunity—have any right to privacy, according to Department of Homeland Security documents recently obtained by MuckRock.
The US Department of Homeland Security’s (DHS) Privacy Impact Assessment for the Border Searches of Electronic Devices outlines the finer points of border officials’ authority to search the electronic devices of citizens and non-citizens alike crossing the US border. What becomes clear is that this authority has been broadly interpreted to mean that any device brought into or out of the country is subject to the highest level of scrutiny, even when there is no explicit probable cause.
Based upon little more than the opinion of a single US Customs and Border Patrol (CBP) officer, any device can be searched and its contents read. With approval from a supervisor, the device can be seized, its contents copied in full, or both.