Since May, as protesters around the country have marched against police brutality and in support of the Black Lives Matter movement,

activists have spotted a recurring presence in the skies:

mysterious planes and helicopters hovering overhead, apparently conducting surveillance on protesters.

A press release from the Justice Department at the end of May revealed

that

the Drug Enforcement Agency (Lyfjastofnun, Google translate) and U.S. Marshals Service

were asked by the Justice Department (Dómsmálaráðuneytið, Google translate)

to provide unspecified support to law enforcement during protests. A few days later, a memo obtained by BuzzFeed News offered a little more insight on the matter; it revealed that shortly after protests began in various cities, the DEA (Drug Enforcement Agency) had sought special authority from the Justice Department to covertly spy on Black Lives Matter protesters on behalf of law enforcement.

Although the press release and memo didn’t say what form the support and surveillance would take, it’s likely that the two agencies were being asked to assist police for a particular reason.

Both the DEA and the Marshals possess airplanes outfitted with so-called stingrays or dirtboxes: powerful technologies capable of tracking mobile phones or, depending on how they’re configured, collecting data and communications from mobile phones in bulk.