Here’s an infographic from Vocativ showing a geographic breakdown of IMSI catchers (also known as stingrays) used by various police forces across the USA. According to the accompanying story there are at least 471 such devices used by law enforcement agencies across the nation. In Canada, a CBC investigation has revealed widespread use of IMSI catchers by local police forces and the RCMP.
But despite their widespread use, police are reluctant to talk about these cell tower-spoofing devices, in some cases lying about their very existence. There’s good reason for that.
First and foremost is the legal issue. Given the power of an IMSI catcher to indiscriminately capture communications from every cellular device within range, they’re understandably illegal for civilians to own and operate. But here’s something that may surprise you: police use might be illegal as well. Defence lawyers in Canada have argued that the RCMP violated the Radiocommunications Act by using unregistered devices that interfere with public airwaves. As for their deployment across the United States, Vocativ notes that the legality of stingrays is still being “figured out” by the court system there. It doesn’t help that agencies who purchase IMSI catchers must often sign an NDA agreement with the companies that provide them; this has, in part, historically led to police denying their possession of them.
Equally troubling is the potential for mass surveillance. In the USA only a handful of states—including California, Utah, Virginia, and Washington—require a warrant for IMSI catcher use. In Canada Chief Superintendent Jeff Adam told the CBC that the RCMP “does not collect voice and audio communications, email messages, text messages, contact lists, images, encryption keys or basic subscriber information.” But there is currently zero oversight to hold that police force to account. You tell us that, unlike the NSA, you don’t collect or store bulk interceptions, and we’re supposed to believe you, just because?
Here’s my real problem with IMSI catchers: how would you self-censor your own communication knowing that at any moment the police could be listening in?