The Internal Revenue Service (IRS) is the latest federal agency known to use electronic cellphone surveillance equipment, according to a new report.

Invoices obtained under the Freedom of Information Act by The Guardian show that the IRS purchased cellphone tracking technology in 2009 and 2012. The equipment, manufactured by Harris Corporation and known as a Stingray, mimics a cell tower and can collect metadata about a call and sometimes even content from calls connected through them.

“The info showing that they are using Stingrays is generally consistent with the kinds of investigative tactics that they are engaging in, and it shows the wide proliferation of this very invasive surveillance technology,” Nate Wessler, a staff attorney with the speech, privacy and technology project at the American Civil Liberties Union (ACLU) told The Guardian.

“It’s used by dozens, perhaps hundreds, of local law enforcement, used by the usual suspects at the federal level, and if the IRS is using it, it shows just how far these devices have spread,” Wessler said.

The newspaper pointed out that agencies have been able to get away with using these devices without a court order; a lower-level order called a PEN register, also known as a “trap and trace,” is enough.

The Guardian was able to figure out the information from a partly redacted invoice from 2012 which indicated that $65,000 was spent by the IRS to upgrade a Stingray II device to a Hailstorm, which is more powerful version of the Stingray. The invoice also showed that $6,000 had been paid to Harris for training in use of the equipment.

Mark Matthews, a former deputy commissioner for services and enforcement at the IRS who now works for the law firm Caplin and Drysdale, told The Guardian that he hadn’t heard any rumors about the use of the devices yet. “So this either hasn’t ripened yet in a tax case, 95% of which [end in a plea deal] so there would be no such disclosures, or this is saved more for money laundering/drug/terrorist-financing-like investigations.

“[It] could be as silly as [they] got to the end of the year, had some extra funds, and somebody said, ‘We need some more of these devices,’” Matthews said. “It could literally be that silly. But it could be something different; it could be that they’ve decided to use them in cases where they’re the primary detective agency, and we haven’t seen it yet in the private sector.”

The criminal investigation division of the IRS employs between 2,000 and 3,000 enforcement agents, each of whom have the authority to get PEN orders for conducting surveillance with Stingrays, according to The Guardian.

Information gathered by the ACLU has revealed there are now—with the addition of the IRS—13 federal agencies known to have Stingray cellphone surveillance devices at their disposal. Among them are the National Security Agency, the Federal Bureau of Investigation (FBI) and the U.S. Secret Service. An investigation into U.S. police agencies, conducted last year by Gannett newspapers, determined that at least 25 of them own a Stingray. In total, the ACLU has identified 57 agencies in 22 states and the District of Columbia that own them.

The U.S. government has essentially placed a net of secrecy over their use and the FBI requires police organizations to sign non-disclosure agreements when being equipped with the devices.

-Steve Straehley, Danny Biederman

To Learn More:

IRS Possessed Stingray Cellphone Surveillance Gear, Documents Reveal (by Nicky Woolf and William Green, The Guardian)

Stingray Tracking Devices: Who’s Got Them? (American Civil Liberties Union)

U.S. Secret Service May Now Track Cell Phones without a Warrant (by Noel Brinkerhoff, AllGov)

LAPD Has Had “Stingray on Steroids” Surveillance Equipment for a Decade (by Ken Broder, AllGov California)

Senate Committee Approves Continued Bulk Spying on Americans (by Noel Brinkerhoff, AllGov)