The U.S. Department of Homeland Security has concocted a remarkable new policy: It reserves the right to seize for an indefinite period of time laptops taken across the border. A pair of DHS policies from last month say that customs agents can routinely–as a matter of course–seize, make copies of, and “analyze the information transported by any individual attempting to enter, re-enter, depart, pass through, or reside in the United States.” DHS claims the border search of electronic information is useful to detect terrorists, drug smugglers, and people violating “copyright or trademark laws.”

This is a disturbing new policy, and should convince anyone taking a laptop across a border to use encryption to thwart DHS snoops. Encrypt your laptop, with full disk encryption if possible, and power it down before you go through customs. Here’s a guide to customs-proofing your laptop published in March.