Following the ruling, there is nothing preventing authorities from a more comprehensive search program, said Fred Schneider, a privacy and security expert and professor of computer science at Cornell University.

"There is a drift in this country toward more surveillance and less civil liberties, and it is eroding step-by-step," Schneider said. "More people might complain if they were searching people at the Lincoln Tunnel, and I don't see how this case is different from that."

The Electronic Frontier Foundation argues that searches of electronic devices at the border will likely only become more frequent, as forensics tools get significantly better. This week, Microsoft announced a set of software tools that fits on a USB drive and gives law enforcement officers the ability to run more than hundred commands quickly and automatically.

"It won't be long before customs agents can efficiently perform a thorough search on every machine," Jennifer Granick, civil liberties director at the EFF, said in a discussion of the impact of the ruling. "So long as there are no protocols or oversight for these searches, every traveler's personal information is at risk."

Encrypting the hard drive, having a separate account on the PC owned by the worker's company, or traveling with a clean laptop and using an encrypted VPN to access data are all possibilities, Granick said. As an example of the difficulty that unregulated searches add to international travel, Granick uses a hypothetical "Alice," an attorney.

"Attorney Alice needs to have confidential attorney-client privileged information overseas," she wrote. "Before departure, she removes unnecessary information, encrypts her hard drive with strong crypto and sets up a login for a protected account and a travel account on her computer. To access the confidential data, one would need to first login to the protected account, and then open the encrypted files. Only Alice’s employer (The Law Offices of Bob) knows the passwords to the account and encrypted data, and keeps them secret until Alice arrives at her destination. Bob then sends the passwords to Alice in an encrypted email message."

Yet, Granick's discussion is peppered with uncertainty. Because the U.S. government has not complied with requests for more information through the Freedom of Information Act (FOIA), the attorney cannot make any strong recommendations.

"There are no options that provide perfect privacy protection, but there are some options that reduce the likelihood that a legitimate international traveler's confidential information will be subjected to arbitrary and capricious examination," she wrote.

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