All across America, from Florida to Colorado and back again, the country's increasingly militarized local police forces are using a secretive technology to vacuum up cellphone data from entire neighborhoods – including from people inside their own homes – almost always without a warrant. This week, numerous investigations by major news agencies revealed the US government is now taking unbelievable measures to make sure you never find out about it. But a landmark court ruling for privacy could soon force the cops to stop, even as the Obama administration fights to keep its latest tool for mass surveillance a secret.

So-called International Mobile Subscriber Identity (IMSI) catchers – more often called their popular brand name, "Stingray" – have long been the talk of the civil liberties crowd, for the indiscriminate and invasive way these roving devices conduct surveillance. Essentially, Stingrays act as fake cellphone towers (usually mounted in a mobile police truck) that police can point toward any given area and force every phone in the area to connect to it. So even if you're not making a call, police can find out who you've been calling, and for how long, as well as your precise location. As Nathan Freed Wessler of the ACLU explained on Thursday, "In one Florida case, a police officer explained in court that he 'quite literally stood in front of every door and window' with his stingray to track the phones inside a large apartment complex."

Yet these mass surveillance devices have largely stayed out of the public eye, thanks to the federal government and local police refusing to disclose they're using them in the first place – sometimes, shockingly, even to judges. As the Associated Press reported this week, the Obama administration has been telling local cops to keep information on Stingrays secret from members of the news media, even when it seems like local public records laws would mandate their disclosure. The AP noted:

Federal involvement in local open records proceedings is unusual. It comes at a time when President Barack Obama has said he welcomes a debate on government surveillance and called for more transparency about spying in the wake of disclosures about classified federal surveillance programs.

Some of the government's tactics to hide Stingray from journalists and the public have been downright disturbing. After the ACLU had filed a records request for information on Stingrays, the local police force initially told them that, yes, they had the documents and to come on down to the station to look at them. But just before an ACLU rep was due to arrive, US Marshals seized the records and hid them away at another location, in what Wessler describes as "a blatant violation of state open-records laws".



The federal government has used various other tactics around the country to prevent disclosure of similar information.

USA Today also published a significant nationwide investigation about the Stingray problem, as well as what are known as "cellphone tower dumps". When police agencies don't have Stingrays at their disposal, they can go to cell phone providers to get the cellphone location information of everyone who has connected to a specific cell tower (which inevitably includes thousands of innocent people). The paper's John Kelly reported that one Colorado case shows cellphone tower dumps got police "'cellular telephone numbers, including the date, time and duration of any calls,' as well as numbers and location data for all phones that connected to the towers searched, whether calls were being made or not."

It's scary enough to think that the NSA is collecting so much information, but this mass location and metadata tracking at the local level all may be about to change. This week, the ACLU won a historic victory in the 11th Circuit Court of Appeals (serving Florida, Alabama and Georgia), which ruled that police need to get a warrant from a judge before extracting from your cellphone the location data obtained by way of a cell tower. This ruling will apply whether cops are going after one person, the whole tower and, one can assume, Stingrays. (The case was also argued by the aforementioned Wessler, who clearly is this month’s civil liberties Most Valuable Player.)

This case has huge implications, and not just for the Stingrays secretly being used in Florida. It virtually guarantees the US supreme court will soon have to tackle the larger cellphone location question in some form – and whether police across the country have to finally start getting a warrant to find out where your precise location for days or weeks at a time. But as Stanford law professor Jennifer Granick wrote on Friday, it could also have an impact on NSA spying, which relies on the theory that indiscriminately collecting metadata is fair game until a court says otherwise.

You may be asking: how, exactly, are the local cops getting their hands on such advanced military technology? Well, the feds are, in many cases, giving away the technology for free. When the US government is not loaning police agencies their own Stingrays, the Defense Department and Homeland Security are giving federal grants to cops, which allow departments to purchase the gear at the cost of $400,000 a pop from defense contractors like Harris Corporation, which makes the Stingray brand.

Speaking of which, the New York Times's Matt Apuzzo wrote another essential, overlooked story this week detailing all of the other free military gear – like machine guns, armored vehicles and aircraft – that police are receiving from the Pentagon. An example from his story about the militarization of what used to be routine police activities also comes from Florida: "In Florida in 2010, officers in SWAT gear and with guns drawn carried out raids on barbershops that mostly led only to charges of 'barbering without a license.'"

Like Stingrays, and the NSA's phone dragnet before them, the militarization of America's local cops is a phenomenon that's only now getting widespread attention. As journalist Radley Balko, who wrote a seminal book on the subject two years ago, said this week, the Obama administration could easily limit these tactics to "cases of legitimate national security" – but has clearly chosen not to.

No matter how much President Obama talks about how he has "maintained a healthy skepticism toward our surveillance programs", it seems the Most Transparent Administration in American History™ remains much more interested in maintaining a healthy, top-secret surveillance state.