The Wall Street Journal has today a terrific article, "Americans' Cellphones Targeted in Secret U.S. Spy Program," that details how U.S. Marshals Service aircraft deploy "dirtbox" technology to spy on millions of Americans' cellphones from above. The dirtbox technology (so named as an acronym for the company that makes the devices, Digital Receiver Technology) functions in much the same way as "stringray" spy technologies which obtain information about the location of a person's cellphone by pretending to be a legitimate cellphone tower. While stingray devices can scoop up information about hundreds of innocent cellphone users, dirtbox devices can pick up information from thousands and tens of thousands of innocent Americans.

From the Journal:

The program is the latest example of the extent to which the U.S. is training its surveillance lens inside the U.S. It is similar in approach to the National Security Agency's program to collect millions of Americans phone records, in that it scoops up large volumes of data in order to find a single person or a handful of people. The U.S. government justified the phone-records collection by arguing it is a minimally invasive way of searching for terrorists. … By taking the program airborne, the government can sift through a greater volume of information and with greater precision, these people said. If a suspect's cellphone is identified, the technology can pinpoint its location within about 10 feet, down to a specific room in a building. Newer versions of the technology can be programmed to do more than suck in data: They can also jam signals and retrieve data from a target phone such as texts or photos. It isn't clear if this domestic program has ever used those features. … Christopher Soghoian, chief technologist at the American Civil Liberties Union, called it "a dragnet surveillance program. It's inexcusable and it's likely—to the extent judges are authorizing it—[that] they have no idea of the scale of it."

With bitter amusement and dismay I noted the juxtaposition of these two headlines in today's Washington Post:

"Marshals said to monitor phones from the air" and "Report: Most think they live in a privacy dystopia."

The second article is reporting the results of a Pew Research Poll which the Post notes:

Eight in 10 Americans believe the public should be concerned about the government's monitoring of phone calls and Internet communications according to a survey conducted by the organization in January.

No kidding. It's beginning to seem like the list of Federal agencies that don't spy on Americans is shorter than the list of those that do.