According to an article in POLITICO based on interviews with unnamed “law enforcement officials,” the US Department of Homeland Security (DHS) is considering expanded use of airline reservation data  to target travelers  for more intrusive searches:

The department could begin analyzing the travel patterns of suspected domestic extremists, monitor flights they book on short notice and search their luggage for weapons, a senior law enforcement official told POLITICO. There have also been discussions about putting suspected domestic violent extremists — a category that includes white supremacists — on the FBI’s No Fly List, the official said. When suspected extremists travel internationally, officials may be more likely to question them before they pass through customs and to search their phones and laptops.

A second law enforcement official told POLITICO that conversations about monitoring domestic extremists’ travel have involved multiple federal agencies at the interagency level, including the FBI.

We’ve recently discussed what’s wrong with the no-fly lists (there are several, created and maintained by different, although interlocking, entities, for different ostensible purposes) and why they shouldn’t be used like this or in most of the other ways that they are now used.

As Gary Leff puts it in his View from  the Wing travel blog:

Denying the freedom of travel, without trial, is precisely the mob rule outside of the rule of law that we’re supposed to be pushing back on after the events of January 6th. Having the government ban travel on all airlines without judicial review is frightening in a democracy.

The latest article in POLITICO suggests tactics that go well beyond no-fly lists. It’s important to understand what’s being talked about, and how it would differ from previously-disclosed practices and exceed what is permitted by current law.

It’s crucial to recognize that, in this proposal, the DHS is testing the waters not for an expansion of existing authority, but an entirely new category of exception to the Fourth Amendment: a “pre-crime” search that is based on neither a warrant nor probable cause, but that — unlike an administrative search — targets individuals selectively.

For more than fifteen years, data about airline passengers provided to the DHS by domestic and international airlines has been used for more than just binary fly/no-fly decisions.

In 2005– as was finally disclosed publicly more than eight years later at trial — the entry for Dr. Rahinah Ibrahim in the DHS “screening” database included a “handling code” indicating what actions airline staff and law enforcement officers were to take if she tried to exercise her right to travel by air. That handling code was not limited to international flights, and was acted on when she tried to board a domestic flight.

The DHS “National Targeting Center” targets passengers for a variety of government intrusions. The consequences of being placed on a so-called watchlist or being flagged by  a  watchlisting algorithm aren’t limited to watching (a/k/a warrantless surveillance), but can include detention, interrogation, and search in addition to denial of travel.

These methods have already been used to target political activists. TECS alerts that are part of the algorithmic ruleset used to process and profile international air travelers have been used to trigger questioning and searches of political activists and journalists at points of entry, including  imaging by DHS of travelers’ electronic devices and storage media.

What appears to be new in the latest DHS trial balloons is the idea of using airline reservation data to target more intrusive warrantless searches on domestic flights.

In the past, while the Transportation Security Administration has sometimes claimed the authority to conduct searches for general law enforcement purposes, that argument has generally fared poorly for the TSA in court.

Despite TSA practices of searching airline passengers for drugs and cash, the current state of the case law is that the authority of the TSA is limited to searches for objects that pose a threat to aviation. And so far as we can tell, while international airline reservations  to and from the US are checked against the FBI’s aggregated and unreliable NCIC database of wants and warrants, domestic US airline reservations are not (yet).

So as Glenn Greenwald has rightly observed, a key aspect of the latest proposals by the DHS is that of expanding to domestic travel exceptions to civil liberties previously tolerated by US courts only outside the US or at or “near” (within 100 miles of) international borders.

Within the US, including at TSA checkpoints for domestic flights, searches have been found Constitutional only (1) on the basis of  a warrant supported by probable cause to believe a crime has been committed, (2) on a limited basis as part of a “Terry stop” supported by reasonable articulable suspicion of a crime, or (3) as an “administrative search” for a limited purpose, to which everyone engaging in a particular activity is subjected equally.

If there is sufficient basis for suspicion of certain “domestic terrorists” or anyone else to justify subjecting them to a more intrusive search than other members of the public when they travel, that can and should be done through applications for search warrants.

Those applications are reviewed and acted on by judges, in adversary proceedings (the subject of a warrant can apply to have it quashed) subject to due process rights.

Law enforcement officers engage in constant profiling. But there is extensive and constantly evolving case law defining which attributes of appearance, behavior, and context provide sufficient basis for suspicion to justify detention, compelled responses to questions, or issuance of a search or arrest warrant.

There were “no-go” lists before the no-fly lists were created: Being listed in NCIC as subject to arrest can be a basis for arrest, even if the listing proves to be erroneous as an indicator of the existence of a valid warrant. But the FBI can’t create its own arrest  entries in NCIC. The FBI can only compile and maintain a list of people who judges have ordered arrested.

The DHS seems to contemplate something entirely different. DHS doesn’t say that it will apply for court orders but that it will make its own decisions — based on either its own lists or algorithmic pre-crime profiling — to target certain individuals for more intrusive search.

Aside from the fact that “precogs” who can predict future crimes are a dystopian fantasy, it’s unclear where in the Constitution the DHS thinks it can find support for this new category of search. We may not know unless and until someone challenges one of these profile-based “pre-crime” searches in court.

Congress, the courts, and above all the American people should say no to this whole idea.