According to flight data, over the weekend an FBI surveillance plane carried out a protracted overflight of the city of Dearborn, Michigan. Some 30% of the city’s population is Arab-American, which has made it a regular target for FBI sting operations.

Despite this, the FBI is loudly denying that the spy plane was conducting surveillance of the Arab-American community in general, insisting they “don’t conduct mass surveillance,” though they did not offer any details on actually what they were surveilling, and maintained there were no threats in the area of the flight, which includes Metro Detroit.

Though some Arab-American groups took that denial at face value, saying there is no reason to doubt the FBI, many aren’t so sure, and indeed the FBI’s overflights of US cities have tended in recent times to be for untoward reasons.

The Justice Department has been conducting such overflights in so-called “dirtbox” planes, which mimic the signals of a cellphone satellite, but being in the air instead of in orbit, are then connected to ordinary Americans’ phones as the closer signal, allowing them to seize cellphone data en masse from the air. The FBI has recently conducted such flights for the Justice Department as well.

If this proves to be the nature of this most recent flight, the FBI could theoretically claim Arab-Americans aren’t being targeted as such. After all, it is everyone who is a target, or at least their cellphones. Still, the FBI’s denial that it conducts mass surveillance as a general rule is demonstrably false, and the overflight is just one more in a troubling trend.