Civil liberties advocates are voicing concerns over the U.S. government’s policy of sharing license plate data collected at the Canadian border with insurance companies.

Licence plate numbers are recorded by a scanner every time a vehicle crosses the border, and recently published documents show the information has been shared with an organization called the National Insurance Crime Bureau since 2005.

The NICB, which is a non-profit group made up of nearly every U.S. insurance agency, says it’s only watching out for stolen American cars, though critics at the BC Civil Liberties Association worry about the potential for further use.

“This is one example of data flowing to people you might not have expected,” said association lawyer Micheal Vonn. “This allows for a tracking that is science fiction for many people, but is being embedded in these systems that can talk to each other.”

U.S. Customs and Border Protection assured CTV News it doesn’t share the data with Canadian insurance companies such as ICBC, and says any information shared is only on a need-to-know basis.

“Federal law also allows CBP to share data with other federal, state, local and international investigating agencies and other organizations engaged in theft prevention,” the agency said in a statement.

“Under a memorandum of understanding, [customs] provides information to NICB to support its mission to prevent and deter vehicle theft.”

The power of licence plate scanning made headlines in June after accused triple-murderer Travis Baumgartner was arrested trying to cross the border between B.C. and Washington State.

Authorities had flagged the truck he was believed to be driving when he left Edmonton, where three people were gunned down during an armored car heist on June 15. A fourth shooting victim survived.

“Our officer in the booth got an instant warning that this vehicle is associated with someone who [may be] armed and dangerous,” CBP chief Tom Schreiber said at the time.

But the potential use of licence plate scanners as a surveillance tool has also been a source of controversy in B.C., where police are being investigated for mounting the devices on patrol cars.

The province’s privacy commissioner launched the probe to determine whether the scanning of innocent people’s vehicles, a program implemented by police in Vancouver and Victoria as well as Mounties, complies with privacy laws.

The results are expected to help determine licence plate-scanning guidelines to be used across B.C.

With a report from CTV British Columbia’s Jon Woodward and files from The Canadian Press