U.S. Customs and Border Protection states that their “top priority is to keep terrorists and their weapons from entering the U.S. while welcoming all legitimate travelers and commerce. CBP officers and agents enforce all applicable U.S. laws, including against illegal immigration, narcotics smuggling and illegal importation” (https://www.cbp.gov/border-security) and in their efforts to do this they have begun to more and more frequently request, require, demand that individuals entering the United States turn over their cell phones/technology devices.
In terms of legality, this is completely within the realm of permissibility in that U.S. Customs and Border Protection has the privilege to conduct, at border crossings, a search of physical items, such as luggage or cell phones, laptops, etc… without a warrant or suspicion of wrongdoing (https://www.aclu.org/other/constitution-100-mile-border-zone?redirect=constitution-100-). A fact that, I believe many of us forget, is that all of our Constitutional rights do not exist along the border and interestingly enough all of our rights do not exist within the U.S.’s ‘border zone’. What is a ‘border zone’ you ask? To be brief, due to a law from 1953, America has a 100 mile perimeter that is considered a ‘border zone’ and within this 100 mile zone U.S. Customs and Border Protection has special powers, rights and permissions. As of today roughly 200 million Americans live within this border zone and several states are entirely within this territory – needless to say our 50th district is entirely within this zone (https://www.aclu.org/know-your-rights-governments-100-mile-border-zone-map; https://www.aclu.org/other/constitution-100-mile-border-zone?redirect=constitution-100-)).
S. 823, “Protecting Data at the Border Act” (which is a genuine bi-partisan endeavor) would put a stop to the searching of technological devices without a warrant at U.S. borders and presumably this would also apply to the 100 mile ‘border zone’. This bill has exceptions for imminent danger and is quite in depth about various aspects but it’s essence is as follows: “[A] Governmental entity may not (1) access the digital contents of any electronic equipment belonging to or in the possession of a United States person at the border without a valid warrant supported by probable cause issued using the procedures described in the Federal Rules of Criminal Procedure by a court of competent jurisdiction; (2) deny entry into or exit from the United States by a United States person based on a refusal by the United States person to [provide access to digital and/or on-line information, or] (3) delay entry into or exit from the United States by a United States person for longer than the period of time, which may not exceed 4 hours, necessary to determine whether the United States person will, in a manner in accordance with subsection (c), consensually provide… access” (https://www.congress.gov/bill/115th-congress/senate-bill/823/text?q=%7B%22search%22%3A%5B%22S.+823%22%5D%7D&r=1).
For more information about the searching of technological devices, which as noted has increased dramatically in the recent past: http://www.nbcnews.com/news/us-news/what-if-u-s-border-agents-ask-your-cellphone-n742511
For an opinion piece by one of the co-sponsors of the bill: http://thehill.com/blogs/congress-blog/judicial/330547-lets-end-warrantless-searches-at-the-border
For The Center for Democracy & Technology endorsement: https://cdt.org/press/cdt-supports-the-protecting-data-at-the-border-act/