American politics may be ideologically divided when it comes to government surveillance—there is probably no better example than Chris Christie’s emotional riposte to Rand Paul’s constitutional swipe at bulk data collection in the first primary debate—but there is one stealthy spy tool that is bringing both ends of the spectrum together in mutual shock and horror.

It’s called “Stingray,” a black box that can mimic a powerful cell tower, tricking wireless devices into communicating information to it and thus giving cops access to a specific target’s location and data. But this technology doesn’t stop there—it also exposes everyone’s devices in the vicinity of the black box, making innocent bystanders vulnerable to the eyes and ears of probing law enforcement.

Local, state, and federal police have been using this kind of technology to surreptitiously monitor the location of suspects for at least 20 years, but thanks to booster products like “FishHawk” and “Porpoise,” which are all made by the same Florida-based Harris Corporation, cops now have the ability to eavesdrop on conversations, and monitor texts as well.

According to this map by the American Civil Liberties Union, (at least) 53 local and state police departments in 21 states across the country are using Stingray technology today. In addition, the ACLU knows of at least 12 federal agencies that use it. Given the secrecy, there could be more. Law enforcement has contended Stingray is for “emergencies,” ostensibly to locate violent criminals and would-be terrorists, but the ACLU has enough documentation to show how often it is used for otherwise, even to monitor peaceful protests.

And they are doing this with or without court orders, say critics, often keeping judges and especially elected officials in the dark through an elaborate veil of vague affidavits, non-disclosure agreements that police sign with both the FBI and Harris Corporation, and appeals to domestic and national security. In other words, even law-and-order advocates and sympathetic magistrates are unsettled at how Stingray is being used right under their noses.

“They are spying on law-abiding citizens as we speak,” charged Rep. Darrell Issa, R-Calif., who has called Stingray “an abusive program,” and successfully passed an amendment to the House Commerce, Justice and Science (CJS) Appropriations Act in June that would restrict the use of the technology without a court order. An original champion of the Patriot Act who spent his four years at the helm of the House Oversight Committee investigating Benghazi, the IRS, Obamacare, and “Fast & Furious,” on this issue Issa appears four-square with the privacy advocates.

When asked by USA Today what the next step was, given that there was no similar amendment in the Senate spending bill, he said, “I will use additional opportunities to get it done. Right now law enforcement won’t tell us how many Stingrays they have. The only way to protect the American people is to change the law.”

In February, Sen. Bill Nelson, D-Fla., called out Stingray and Harris Corporation on the Senate floor for the first time—a pivotal moment, advocates say.

“Employed for a national security, for our national safety, which is the job of government, then it’s a good thing,” Nelson said. “Employed, however, for other reasons of invading our Constitutional right to privacy is another thing. It is time to stand up for the individual citizen in this country and their right to privacy.”

Meanwhile, Sen. Ron Wyden, D-Ore., and Rep. Jason Chaffetz, R-Utah, the new Oversight and Reform Committee Chairman, have targeted Stingray in a pair of bills demanding agents show probable cause before using any sort of GPS tracker, not just Stingray. This, they say, would affirm the Supreme Court’s view in United States v. Jones, which in 2012 said the GPS tracking of a suspect constituted a search under the Fourth Amendment. That case focused on police and a target under warrant—it did not even begin to consider the innocent bystanders who might get swept up in a Stingray dragnet.

“Right now there is no consistent legal framework in place,” Wyden spokesman Keith Chu tells TAC. “I think it’s clear that the lack of a coherent legal framework, a lack of any kind of clear rule of how this kind of technology or other tracking device takes place, is something that should concern everyone in my opinion, no matter where (on the political spectrum) you fall.”

The more one learns about Stingray the worse it seems to get. According to reports this year, this kind of technology can disrupt phone signals from other towers in the vicinity to give police a clear shot at their target, potentially putting emergency calls at risk. Furthermore, reports late last year indicate U.S. Marshals have been flying aircraft outfitted with these devices, gathering data from countless numbers of cell phones in every flight.

In a more recent report, the Associated Press said it analyzed scores of flight data and found the FBI ran more than 100 flights over 11 states over a 30-day period this spring. The 50 Cessna aircraft, whose pilots were connected to fake front companies, were equipped with heavy duty cameras, “and in rare circumstances, technology capable of tracking thousands of cellphones, raising questions about how these surveillance flights affect Americans’ privacy,” according to the AP.

The FBI confirmed their use, but said the planes were not used for mass surveillance. Furthermore, the FBI insists police always get court orders for Stingray, with of course, a number of exceptions, including its deployment in “public spaces” and for “emergencies.” Privacy experts say these loopholes are big enough to fly a Cessna through.

Sens. Chuck Grassley, R-Iowa, and Patrick Leahy, D-Vt., chairman and ranking member of the Judiciary Committee respectively, penned a lengthy letter in December to then-Attorney General Eric Holder and Department of Homeland Security Secretary Jeh Johnson, asking not only about the planes, but the “exceptions” to seeking Stingray warrants. A similar letter was signed by a group of Democratic senators, including current Democratic primary candidate Bernie Sanders of Vermont.

“The Fourth Amendment protects Americans from unwarranted searches and seizures, so we need a better understanding of how this technology is being used, including the legal authority agencies obtain prior to deploying these tools, the specific information they are giving to judges when requesting to use them, and what policies are in place to ensure the civil liberties of innocent Americans are protected,” Grassley’s office said in a statement forwarded to TAC on Aug. 14.

Clearly in response to congressional pressure—as well as mounting legal battles in a number of states—the Justice Department announced in May that it will conduct its own internal review. According to the Wall Street Journal, a Justice spokesman said the department is “examining its policies to ensure they reflect the Department’s continuing commitment to conducting its vital missions while according appropriate respect for privacy and civil liberties.”

This is nothing more than an afterthought, Neema Guliani, legislative council for the National ACLU, tells TAC. “Why are we having a conversation about whether the policies and practices are appropriate after a decade of you using them?”

The FBI might say, “trust us,” but the truth of the matter is, Stingray would be just another fish in the sea if news organizations and civil liberties advocates weren’t beating the rushes for evidence everyday. It’s been such a secret it has taken years for advocates to get a handle on it.

How? Police departments are forced to sign non-disclosure agreements with the FBI when they purchase “Stingray”—at least $400,000 a pop. This keeps the lid on how and when it is used, and in court, ACLU cites numerous examples of the government getting cases dismissed or negotiating plea deals in order to avoid talking about the Stingray on the record.

In some cases, police have purposefully concealed their use at all in official affidavits. As a result, federal judges have been hoodwinked, thinking they are being asked to sign off on routine wiretaps, rather than cell simulators. In this email thread obtained by the ACLU, a Sarasota, Fla., sergeant suggests a fellow officer mucked things up when he gave away too much about the technology investigation in a case report:

In the past, and at the request of the U.S. Marshals, the investigative means utilized to locate the suspect have not been revealed so that we may continue to utilize this technology without the knowledge of the criminal element. In reports or depositions we simply refer to the assistance as ‘received information from a confidential source regarding the location of the suspect.’ To date this has not been challenged, since it is not an integral part of the actual crime that occurred.

Some judges who have gotten wise to Stingray, however, have started imposing stricter rules for cops who want to use it. After finding out about Stingray through local news reporting, judges in Tacoma, Washington, are now forcing police to spell out what they want, and how they are going to get it without infringing on the rights of bystanders. It’s now a state law in Washington.

But while one jurisdiction seems hip to the trick, others remain ignorant, in many cases because they don’t have a choice. Harris Corporation, in conjunction with the FBI, have gagged local police departments with non-disclosure agreements that require complete silence about how Stingray and its cousins work, even during the acquisitions process.

Joe Simitian, a Clara County, Calif., supervisor, told the New York Times in March that he was floored by his sheriff’s request to buy Stingray without even the basic details of how it worked:

“So, just to be clear, we are being asked to spend $500,000 of taxpayers’ money and $42,000 a year thereafter for a product for the name brand which we are not sure of, a product we have not seen, a demonstration we don’t have, and we have a nondisclosure requirement as a precondition. You want us to vote and spend money,” he continued, but “you can’t tell us more about it.”

The Harris Corporation did not respond to a request for comment for this story. In a clarification in May, the FBI said the non-disclosure agreements do not prevent officers from revealing that Stingray has been used in an investigation and denied that cases have been dismissed before acknowledging Stingray’s use in court depositions.

Guliani doesn’t buy it. “There has been a concerted effort to hide these devices from the public and even to members of congress,” she said. “You are hiding this from people who are responsible for providing oversight and making sure they are used properly.”

For now, despite bipartisan disgust, there are no new hearings planned on the issue, and so far, the legislation championed by Wyden and Chaffetz has gone nowhere. “There are going to be new devices and new ways to track people,” insisted Chu, Wyden’s spokesman.

“Senator Wyden will keep working to move this forward.”

Kelley Beaucar Vlahos is a Washington, D.C.-based freelance reporter and TAC contributing editor. Follow her on Twitter.