It can be difficult to understand the intent behind anti-terrorist security rules on travel and at the border. As our board member Bruce Schneier has vividly described, much of it can appear to be merely "security theater"—steps intended to increase the feeling of security, while doing much less to actually achieve it.

This week the U.S. government, without warning or public explanation, introduced a sweeping new device restriction on travelers flying non-stop to the United States from ten airports in eight Muslim-majority countries, and nine airlines from those countries. Passengers on these flights must now pack large electronics (including tablets, cameras, and laptops) into their checked luggage.

Information is still emerging regarding the rationale behind the ban, which went into effect at 3:00 Eastern Time Tuesday morning. The United Kingdom on Monday joined the United States with a similar regulation aimed at a differing set of flights.

These new restrictions on the transport of digital devices that have provoked a growing sense of insecurity among personal and business travelers flying between America, the Middle East and Turkey, and rightly so. Travelers to and within the United States were already concerned over reports of increasing levels of warrantless inspection of their devices at the border of the United States. Earlier this month, U.S. Customs and Border Protection revealed that there were more device searches in February alone than were conducted in the whole of the 2015 fiscal year.

One of the few consolations is that these invasive searches take place with your knowledge, during security searches of your body and personal items. As we recently described in our guide to digital searches at the border, and in our brief to the Fourth Circuit Federal Court of Appeals, the U.S. border is not a rights-free zone: searches should be noted, and if known about, can be challenged as unlawful. There is also the small compensation that, if officials do not demand access to your laptop, tablet or phone, you can at least be confident that your digital possessions have not been invasively searched.

Requiring digital devices to be checked as luggage removes those reassurances, and adds new concerns. If someone else has physical access to your device almost all information security guarantees are off the table. Data can be cloned for later examination. If you encrypt your stored data, you might limit how much direct data can be extracted—but even so, you cannot stop the examiner from installing new spyware or hardware. New software can be installed for later logging or remote control; protections can be disabled or manipulated.

Under these conditions, it's very hard to make any assurances about how safe your personal data can be in transit. Some security researchers have devised exotic ways to reveal physical tampering; others spend their time defeating those systems. But if your device is out of your possession, all bets are off.

This is not to assert that the new regulations are intended to enable these widespread, unaccountable searches. But given the content of the new regulation and the manner in which it was introduced, it's not surprising that rather than improving the confidence of travelers that their life and possessions remain safe and secure, it's led to even more doubt and uncertainty.

Because the United States authorities has provided little transparency into or notice of their decision, we have no idea what protection this regulation is attempting to provide. It is particularly unclear what the security benefit of limiting the ban to a few airlines and airports achieves. (Even if you believe, as officials within the Trump administration have stated, that some nationalities pose a particular threat, potential terrorists are surely smart enough to fly to an intervening nation which has not imposed the same controls, and take one of the multi-stop flights on which the United States still permits laptops as a carry-on.) At best, it seems like the real threat is so limited that the United States feels it not worth the cost to inconvenience other travelers. At worst, it adds to the sense that some crossing the border—for instance, citizens of these nations and American visitors to them—should have fewer protections and practical opportunities for legal defense against invasive searches at the border than others.

Security theater, or not, improving security at the border includes as a goal ensuring the sense of security and confidence that travelers have that their personal data and devices are safe from unlawful interference. To do that, the United States authorities needs to be more transparent in its reasoning, more protective of the highly personal information held on digital devices, and far less arbitrary in its search and treatment of different groups of travelers. A strong set of legal safeguards consistent governing digital device searches of every traveller—whether they are U.S. citizens, residents, or visitors—would be more secure, and safer for all.

For practical advice for protecting your data at the border, see our detailed new guide and printable border search pocket guide.