Arnold

We must decide whether customs officers at Los Angeles International Airport may examine the electronic contents of a passenger’s laptop computer without reasonable suspicion.

I

On July 17, 2005, forty-three-year-old Michael Arnold arrived at Los Angeles International Airport (“LAX”) after a nearly twenty-hour flight from the Philippines. After retrieving his luggage from the baggage claim, Arnold proceeded to customs. U.S. Customs and Border Patrol (“CBP”) Officer Laura Peng first saw Arnold while he was in line waiting to go through the checkpoint and selected him for secondary questioning. She asked Arnold where he had traveled, the purpose of his travel, and the length of his trip. Arnold stated that he had been on vacation for three weeks visiting friends in the Philippines.

Peng then inspected Arnold’s luggage, which contained his laptop computer, a separate hard drive, a computer memory stick (also called a flash drive or USB drive), and six compact discs. Peng instructed Arnold to turn on the computer so she could see if it was functioning. While the computer was booting up, Peng turned it over to her colleague, CBP Officer John Roberts, and continued to inspect…