HALIFAX -- Nova Scotia's privacy commissioner is investigating after images of students on security cameras at a Cape Breton school were streamed on the Internet, raising fresh questions about reasonable surveillance.

Catherine Tully said Thursday a brief look at the website insecam.org suggests dozens of other webcams in the province and likely around the country are also streaming there.

"My strong advice to anybody who has a video surveillance system, whether they're individuals or businesses or public bodies, is: go to that website and see if your system's there," Tully said in an interview.

"Change your password. Secure your data."

The website registered in Russia bills itself as the world's largest directory of online surveillance security cameras. Images in the past have included everything from sex in private homes to children recorded on so-called nannycams as they slept.

A spokesman for the Cape Breton school board said Thursday it learned Wednesday of the issue after a local reporter was tipped that detailed images of pupils at the school, aged five to 18, were appearing on the website.

Lewis MacDonald, manager of buildings for the Cape Breton-Victoria Regional School Board, said footage included kids drinking from a water fountain and playing in the outdoor yard. Passwords were changed right away and the matter seems to be fixed, he said in an interview.

MacDonald said he wasn't sure if simple default passwords that came with the cameras, which can easily be breached, were changed when the devices were installed over the last two years at the Rankin School of the Narrows in Iona, N.S.

The board has 40 schools and "hundreds of cameras" operating 24 hours a day mostly to prevent vandalism, he added. The board is now reviewing what went wrong.

Tully said she has the power to investigate when there's reason to believe a public agency is not complying with privacy laws.

"Video surveillance, in my view, is a highly privacy-invasive technology. When organizations and public bodies use this technology, they need to first do a proper assessment to ensure that they are respecting the privacy of individuals."

Privacy lawyer Karen Eltis, a law professor at University of Ottawa, said with data and image collection comes great responsibility -- especially in the borderless world of the Internet.

"There needs to be a purposeful approach to surveillance, one that is proportional and, borrowing language from the Charter, which is minimally invasive," she said in an interview.

"What are the cameras there for? Why are there cameras at the water fountain?"

Eltis said it's all about balancing competing rights and interests. The desire to wipe out vandalism must be weighed against protection of privacy and risks associated with recording video footage of a vulnerable population, she added.

"Any superfluous or excessive collection of data can lead to tremendous trouble, all the more so and certainly when you're dealing with children."

Jennifer Rees-Jones, a senior adviser for investigations with the Office of the Privacy Commissioner of Canada, said the Russian website has raised major concerns since 2014.

"The footage that's shown on these Internet-connected cameras can be very, very sensitive -- especially when they're used in private homes or schools."

Consumers who think their webcam is secure should read fine print and double-check.

Rees-Jones said federal privacy investigators have written to the website operators in the past asking them to remove footage from unsecured webcams.

Such traffic seemed to lessen for a while but has since picked up, she said from Toronto.

"We've recently become aware that once again they appear to be posting webcam footage from private spaces."