In a Charter of Rights and Freedoms case last June, the high court abruptly ended the ability of police to informally request subscriber information from internet service providers (ISPs), saying officers must first obtain a production order or warrant from a judge.
The ruling immediately ended all so-called law enforcement requests to ISPs such as Rogers, Shaw and Bell, replacing them in part with time-consuming paperwork that has sharply reduced the number of cases that can be pursued by police.
An internal document shows there were 1,038 such informal requests sent to ISPs in 2013 by the National Child Exploitation Co-ordination Centre, an RCMP-run agency in Ottawa that acts as a hub for police forces in Canada fighting internet-based child sexual abuse.
And in the half-year until the Supreme Court decision on June 13 last year, known as R. vs. Spencer, the centre had already filed 726 such informal requests, a 50 per cent increase in caseloads to that point.
But after that date, there are none.
The RCMP now are limited to filing "jurisdictional requests," which simply ask an ISP for the city and province of a suspect IP address and whether the company will be retaining the subscriber's full information record for at least 60 days. Previously, full details of the identity of the subscriber were turned over to police.
Sharp drop in cases
In the last six months of 2014, following the Supreme Court decision, the centre filed just 56 of these jurisdictional requests, indicating a sharp drop in the cases the RCMP are able to develop and a much thinner flow of investigative information about child sexual predators on the web.
"On an operational level, the Spencer ruling and the broader ISP response are having an ongoing impact on law enforcement and criminal investigations," says an internal RCMP report, obtained by CBC News under the Access to Information Act.
A Rogers transparency report for 2014, released earlier this year, also reflects that sharp decline. The company says it received 384 child-exploitation assistance requests from police that year compared with 711 in 2013. The Rogers report notes the Spencer ruling has severely reduced the numbers.
An RCMP spokesman confirmed the court decision has hampered the ability of police to track down Internet child abusers.
The ruling "has added extra administrative steps to such investigations by requiring police to obtain production orders for basic subscriber information," said Sgt. Harold Pfleiderer.
"Now, investigations of online child exploitation usually take more time. In many cases, there is insufficient information for police to obtain a production order even with the jurisdictional request information."
Sometimes, international police agencies will provide RCMP with nothing more than the IP address for the computer used by a suspected child sexual exploiter active in Canada.
"This is often the only piece of information that the NCECC will receive," he said. "This is usually insufficient in obtaining a production order for basic subscriber information."
The Supreme Court ruling suggested the government could pass a "reasonable" law to allow police to obtain basic subscriber information from ISPs, but a spokesman for Public Safety Minister Steven Blaney indicated that is not yet in the works.
"Our government is currently reviewing the decision," said Jeremy Laurin.
Tips playing field
A spokeswoman for a Winnipeg-based group that fights child sexual abuse says the Spencer decision tipped the playing field, reducing the ability of the police to chase down abusers.
"This has created a tremendous amount of additional work for police," said Monique St. Germaine, general counsel for the Canadian Centre for Child Protection, Inc.
"It means some investigations perhaps don't get off the ground because you have to decide where you're going to put your resources."
Local police forces are also coping with the trickle-down effects of the Spencer ruling. The RCMP had previously sent municipal officers detailed information identifying alleged abusers so they could quickly apply for a judge-approved production order or warrant.
Now, the RCMP can provide only scant information about what city and province the alleged abuser lives in, and what ISP is being used — details often insufficient to present to a judge for a warrant or production order.
"It's creating a lag in our investigations," said Sgt. Maureen Bryden of the Ottawa police online porn unit. "It's taking more time for us to get to the serious investigations."
"Whose rights do you really think are more important?" she said, criticizing the Supreme Court ruling. "The victim child that's being sexually exploited? Or the offender?"
Follow@DeanBeeby on Twitter