For nearly two decades U.S. law enforcement agencies have used counter-terrorism devices known as “stingrays” after the brand name of one variant or ISMI (international mobile subscriber identity)-catchers to track locations in domestic investigations, but information about the devices has been kept carefully under wraps from the public and sometimes even from judges authorizing its deployment. Last week an Arizona judge ruled that a tracking warrant used to deploy the device against Daniel David Rigmaiden, who is accused of collecting millions of dollars in rebates by submitting fraudulent tax returns, was valid despite the fact that the FBI failed to disclose they would be using a stingray or explain how the devices functioned in that warrant.

Much of what is known about their current use in the U.S. comes from a treasure trove of heavily redacted documents being dripped out month by month thanks to an Electronic Privacy Information Center (EPIC) Freedom of Information Act (FOIA) lawsuit and a handful of public cases like Rigmaiden that have been released publicly. Speaking at a Yale Information Society Project (ISP) on biometrics and location tracking earlier this year, EPIC Appellate Advocacy Counsel Alan Butler noted:

“The biggest problem I see with stingrays is the secrecy aspect — The fact that we don’t know how they are used, how exactly they work, what different techniques are available [...] The accountability measures that would be in place for other warranted, more standard surveillance methods are really nonexistent here.”

One thing we do know, according to statement at the same conference from the American Civil Liberty Union’s (ACLU) Chris Soghoian, is that stingrays work by essentially exploiting a security vulnerability in cell service technology: Phones are constantly searching for the nearest signal so they know what tower to connect to when a call comes in, and phones will automatically connect to any tower identifying itself as having the strongest signal strength from your carrier.

The device sends out a signal pretending to be a nearby cell tower with the strongest signal, tricking phones into connecting and allowing the operator to harvest identifying information about devices in the form of the unique ID string of numbers associated with the device known as ISMI and in some variants even communications content, although U.S. law enforcement generally denies using them for the latter need. Whenever a phone is powered on, you can measure the strength of the phone responding to this signal and triangulate a location. This graphic adapted from one in Jennifer Valentino-Devries’ excellent Wall Street Journal coverage of the Rigmaiden case in 2011 shows how it works:

Due to the nature of the devices, they gather up all information within a certain signal range including information about non-target devices — meaning innocent bystanders are having their data sucked up as well. In court documents associated with the Rigmaiden case the FBI requested permission to “expunge” all data obtained in the process, but how much data operators generally have access to during the surveillance process or if that is the standard practice remains unclear leading to a number of questions about whether or not the Fourth Amendment rights of the general public are being compromised. Soghoian noted as much at the Yale ISP conference, saying “No matter how the stingray is used — to identify, locate or intercept — they always send signals through the walls of homes [...] The signals always penetrate a space protected by the Fourth Amendment.”

There are a variety of situations this could be used unrelated to criminal investigations, like aiding search and rescue teams, but when it’s used by law enforcement it’s usually because the phone company can’t find the phone for some reason (such as lacking a GPS chip), to identify what phones are being used by a suspect in a burner type situation (think the Wire), or when the phone company refuses to help with an investigation. But the legal framework for deployment in the United States is murky.

In the Rigmaiden case a warrant was sought because they were after the signal on a mobile wireless card believed to be within his residence where he might have a reasonable expectation of privacy. But FBI and Department of Justice officials have claimed investigators’ stingrays should be treated like “pen registers.” Pen registers are a category of tools that gather information on outgoing calls — normally, the numbers dialed on a particular phone — but don’t receive the content of the communications and do not require a warrant to deploy. Instead, they are allowed under the Electronic Privacy Communications Act of 1986 (ECPA) with a court order that only requires investigators to believe information gathered as a result of the order is likely to assist an ongoing investigation, a lesser standard than probable cause.

However, some judges have found that location information is more intrusive type of surveillance than call logs, and across the field courts appear to be applying different standards — with the prosecution in Rigmaiden saying that “decisions are made on a case-by-case basis” by magistrate and district judges. In US v. Jones, the Supreme Court ruled a GPS tracking device being placed on a suspect’s car constituted a search, but did not rule on if the search was warranted or constitutional.

Due to the lack of disclosure used by investigators pursuing stingray deployment, it is also unclear how often the devices are being used by law enforcement although evidence suggests they are being deployed in at least a handful of states. Reporting from the LA Times uncovered 21 uses of the devices by the LAPD in a four month period in 2012 “apparently without the courts’ knowledge that the technology probes the lives of non-suspects who happen to be in the same neighborhood.”

The lack of clarity around almost every aspect of stingray tech and its use by law enforcement did not happen by accident: The FBI delayed releasing the documents now being released thanks to EPIC’s FOIA lawsuit, only acquiescing when being ordered by a federal judge “to produce all records, except those subject to classification review, by August 1, 2013,” and among the documents already released in that inquiry was a nondisclosure agreement preventing FBI staff from discussing the technology.

Twelve years ago, William Binney resigned from his post as a technical director at the National Security Agency over its domestic surveillance program. “The reason I left the NSA was because they started spying on everybody in the country,” he said in August. In light of revelations from the scandal surrounding General David Petraeus that the FBI was reading the emails of Petraeus, General David Allen and several other suspected players, Binney is reiterating that the FBI is collecting everybody’s emails, and can use the information collected against anybody it wants. In an interview with RT, Binney says:

[T]he FBI has access to the data collected, which is basically the e-mails of virtually everybody in the country. … All the congressional members are on the surveillance too, no one is excluded. … So, yes, this can happen to anyone. If they become a target for whatever reason – they are targeted by the government, the government can go in, or the FBI, or other agencies of the government, they can go into their database, pull all that data collected on them over the years, and we analyze it all. So, we have to actively analyze everything they’ve done for the last 10 years at least.

To those who say they have nothing to hide, Binney cautions, “The problem is if they think they are not doing anything that’s wrong, they don’t get to define that. The central government does … if their position on something is against what the administration has, then they could easily become a target.”

NSA Director Gen. Keith Alexander has said the agency “absolutely” does not keep files on Americans – an assertion Binney called “word games.

The Petreaus investigation comes amid increasing evidence that privacy protection is becoming little more than a pipe dream, with the New York Police Department amassing call logs, an increasing number of cities scanning license plates, and wireless carriers responding to more than a million law enforcement requests for subscriber information that includes location data.

To address some of this concern, Congress is now mulling changes to the Electronic Communications Privacy Act to limit warrantless access to cloud data. The amendments passed by the Senate Judiciary Committee would require a warrant for access to electronic communications that are more than 180 days old (newer emails already require a warrant). But accessing cloud data is seemingly a separate endeavor from searching emails and other data that the government may already have access to via an in-house database of the type described by Binney. Binney was reportedly one of the primary sources for a Wired Magazine exposé on NSA’s construction of a massive center to “intercept, decipher, analyze, and store vast swaths of the world’s communications” in Bluffdale, Utah.

Rep. Jim Renacci (R-OH)

TNR explains:

Renacci’s biggest single source of support, however, has been Suarez Corporation Industries, a large direct-marketing company in North Canton that sells a motley mix of products (space heaters, collectible coins, jewelry, and more). Last year, The Toledo Blade noticed that many large contributions were being made to Renacci by Suarez’s non-executive employees. Seventeen employees, plus six spouses, had given to Renacci, Mandel, or both, with most giving at the maximum allowable level, for a total of $100,000 for each candidate. (Company founder Benjamin Suarez had himself given the maximum to both candidates.) This sort of pattern raises red flags: Federal law bars employers from reimbursing employees for giving to a certain candidate—a method employers could use to evade limits on their own giving.

While companies often encourage employees to “bundle” contributions to candidates who support their interests, it is illegal to coerce employees to donate or to reimburse them for their contributions. Many of the donors had no history of political giving and lived in modest homes. One of the Suarez employees, copywriter Michael Blubaugh, joined with his wife Donna to give $10,000 to Renacci and $10,000 to Mandel. She told TNR that she had been interviewed about the donations by the FBI and that the donations were all made freely, out of their savings. She did acknowledge that, though $10,000 of the money was donated in her name, her husband “made the decision,” not she.

The company has denied reimbursing employees and has refused to “respond to gossip, rumors, or innuendo concerning its operations.”

But if indeed it turns out these were improper contributions, the Mandel and Renacci campaigns may find themselves having to refund a combined $200,000.

J. Edgar Hoover

The ACLU explains:

The FBI’s targeting of American Muslim religious organizations for secret intelligence gathering raises grave constitutional concerns because it is an affront to religious liberty and equal protection of the law. The bureau’s use of outreach meetings to gather intelligence also undermines the trust and mutual understanding necessary to effective law enforcement. Additionally, the FBI’s retention of information gathered through “mosque outreach” in its intelligence files violates federal Privacy Act prohibitions against the maintenance of records about individuals’ First Amendment-protected activity.

But this would hardly be the first time the FBI spied on peaceful Americans.

Here are just a few recent examples: