Visitors to Toronto last week were tracked with surveillance cameras and had their movements streamed on a live billboard, all to promote Oliver Stone's film "Snowden."

To market the film about surveillance whistleblower Edward Snowden, showing at the Toronto International Film Festival, DentsuBos and Elevation Pictures set up cameras equipped with motion tracking technology, around Dundas Square, Canada's busiest intersection. For two weeks they tracked and follow pedestrians from afar while live streaming the footage onto the giant video board. Those caught on camera, according to the agency, felt "violated" while others described it as "the creepiest thing ever."