Lawful surveillance

It's always a challenge to balance the effective use of electronic evidence gathering against the protection of citizens' privacy rights. Canada's experience in this area over the last decade and a half is a case in point.

In 2003, the Criminal Code was amended to allow police to use a "number recorder," a device that could log the list of numbers incoming and outgoing from a phone line.

Before long, investigators were arguing technology had outpaced their ability to surveil suspects. They had a point: American law enforcement had been using number recorders for decades.

Other countries, in the years prior, began working to bring their legal regimes up to speed with internet and mobile technology. But Canada was only just getting around to warrants for call logs.

It would take a decade of both Liberal and Conservative governments introducing legislation — including the spectacular fight over then-Public Safety Minister Vic Toews' lawful access bills — for the Criminal Code to see modern changes to its lawful access regime.

That came in 2015, when section 492.2(1) of the Criminal Code was amended to allows for the use of "transmission data recorders," under what's known as a TDR warrant, thereby replacing the old number recorder provision entirely. The new provision, however, maintained the same standard — "reasonable grounds to suspect" — to obtain a warrant.

There was little disagreement that the Criminal Code was out of date and needed updating, given the changing habits of Canadians who were making daily use of smartphones, text messaging, and email.

At committee, however, there were warnings that lawmakers may have failed to fully grasp just what that technology would be capable of.

At the time, the Canadian Bar Association recommended that the threshold for the transmission data recorders be raised to "reasonable grounds to believe." As Marian K. Brown, then representing the CBA at the House of Commons justice committee explained, "because transmission data may reveal private conduct."

Halifax-based lawyer David Fraser raised similar concerns, noting that "transmission data in the internet age is very different from transmission data in the traditional plain old telephone system."

A recent Alberta provincial court ruling shows precisely how those concerns may have been prescient.

The case turns around exactly how police obtained the phone numbers and identities of two men suspected of running a drug ring in Calgary.

In 2017, investigators in Calgary were surveilling the suspected owner of a drug stash house. They got judicial authorizations to track him, tap his phone lines, and search the residence. But at one point, they observed the suspect using phones that weren't being picked up on their wiretaps. To remedy that, police deployed a cell-site simulator (sometimes called a mobile device identifier, IMSI-catcher, or by the brand name Stingray.) The investigators already had a TDR warrant to use the device.

Devices such as these are, at a minimum, capable of collecting and identifying code associated with all cell phones in a certain radius. Though the process of elimination, it can help cops pick a suspect's cellphone out of a crowd.

The Calgary cops identified the two mystery phones, which they subsequently tapped. That led to the identification of a new suspect in the case, who would later face a variety of drug and weapons charges.

At trial, the accused challenged the use of the cell-site simulator as a violation of Section 8 Charter rights. Law enforcement countered that it had reasonable grounds to believe that the suspect was using new devices, and that deploying the cell-site simulator would identify those them — and potentially other suspects. That means they were relying on a significantly higher standard than that required by the TDR warrant.

Judge Harry Van Harten, in a carefully worded decision, found that the use of the cell-site simulator "was not an act of 'unfettered discussion,'" citing a wide array of case law on surveillance.

Notably, however, Justice Van Harten accepted that the Crown ought to disclose exactly which model of cell-site simulator was used, and what it could do. Investigators and Crown prosecutors, in similar cases, have resisted that sort of disclosure, fearing that publication of the capabilities of these devices could hinder future investigations. And yet there is ample evidence that these devices are capable of much more than merely identifying cellphones. They could be used to triangulate a suspect's location, making them a sort of tracking device. They may even be capable of intercepting communications.

It all goes to the heart of whether the Criminal Code has kept up with the times.

"The Criminal Code is stuck in the past when it comes to surveillance technologies," says Nader Hasan, a partner at Stockwoods. "There is nothing in the Code specifically addressing IMSI catchers, new internet surveillance techniques or artificial intelligence."

Indeed, investigators have had to either mold existing authorizations to fit a specific situation, or rely on a broader general warrant.

That practice isn't inherently wrong. Legislators will never keep pace with technology, meaning the Code has to be flexible.

"Focusing on the type of authorization is, in my view, not the right question," says Leah West, a lecturer at the Norman Paterson School of International Affairs at Carleton University. The right focus, she says, is figuring out whether "the threshold for the lawful collection of information available through the use of a certain technology [aligns] with the reasonable expectation of privacy Canadians have in the information being sought by law enforcement?"

Still, fitting new powers into old rules needs to be done carefully, says West, who served as counsel for the Department of Justice, and sat on the committee which drafted Bill C-59, the Liberal government's national security oversight legislation. "Shoehorning new technological tools into current authorizations is problematic if the result is that the balance is off in either direction."

Even still, Parliament has, traditionally, attempted to adopt new authorization regimes to reflect technological trends — wiretaps, in particular. "There has not been a similar technological awakening since the arrival of the digital age, despite pleas from lawyers, academics and privacy watchdogs," Hasan says.

Of course, previous governments have tried to create new legal regimes for new technologies and surveillance powers. Except for C-13, plans have been shelved due to vigorous opposition.

Cell-site simulators offer an interesting illustration. As the Calgary judge noted, there is no particular Section 8 issue with using such a device to obtain the identifying number, or IMSI, for that phone. But these simulators do not affect just one phone.

"By mimicking a cellular tower, it intercepts the data of every cell phone number communicating within a given radius," Hasan says. "In a busy, urban setting, that can mean tens of thousands of innocent users get swept up during the course of a few hours."

Comparing a transmission data recorder to a cell-site simulator, he says, "is a bit like comparing a pistol to a nuclear bomb. They both do the same thing but on vastly different orders of magnitude." That's to say nothing of this hardware's capability to physically track suspects.

West says it's the Crown's responsibility to ensure that the court is fully aware of the privacy impact of those devices.

"Anyone seeking to obtain a judicial authorization is duty-bound to tell the court what will be sought through the use of any technological tool and what might be incidentally collected, and the judge is equally obligated to assess the corresponding privacy implications before authorizing its collection," she says. The Calgary investigators, who disclosed some of their hardware's capabilities and employed the higher judicial threshold, appear to be a good example of striving to hit that balance.

While the courts are still figuring out exactly how to grapple with the advent of this sort of technology, part of the argument is that they shouldn't have to.

"We need to update the Criminal Code to include comprehensive schemes dealing with new technologies — something akin to Part VI of the Criminal Code, which addresses wiretap authorizations," Hasan says. With that should come a re-drawing of the line between content and transmission data, or metadata.

"Metadata can be intensely revealing and, in some cases, far more revealing than the content of a message itself. Where you were when you sent a given message (the geolocation metadata) is often far more revealing than the message itself (the content). Privacy protections ought to reflect this reality," Hasan argues.

At the same time, West says that the Criminal Code can't be devised in such a way that makes it nearly impossible for investigators to obtain basic information. Cell-site simulators are effective at identifying a suspect's cellphone. Sometimes, they are the only way to do so. But they have become virtually indispensable to law enforcement without the public — or, in some cases, the courts — fully understanding their capabilities.

West proposes instead that it be possible to challenge warrants in closed proceedings. "Law enforcement shouldn't be in the position of having to reveal intellectual property or technical vulnerabilities, which could endanger not only ongoing investigations but Canadian information security, in order to use lawfully collected evidence in a prosecution."

Hasan says new powers should be considered to widen the usage of amicus curiae to advocate for privacy interests while considering the deployment of this sort of technology.

The more time passes, the more technology is sure to come online to put a finer point on the tension between the necessity of that technology and the higher-end capabilities they offer.