Piracy north of the border has exploded in the two years since Congress made it a crime to use video recording devices to copy movies in U.S. theaters, according to industry officials. But with piracy laws more relaxed in Canada, bootleggers can operate there almost risk free, the Los Angeles Times reports.

A frustrated Warner Bros. Entertainment Inc. this week canceled all promotional public screenings in Canada, including any for its big summer movies “Ocean’s Thirteen” and “Harry Potter and the Order of the Phoenix.” The studio estimates that 70% of its releases during the last 18 months have been illegally recorded in Canadian theaters.

“Within that first week, you can almost be certain that somewhere out there a Canadian copy will show up,” said Darcy Antonellis, senior vice president of worldwide anti-piracy operations for Burbank-based Warner Bros.

About 1 in 5 pirated movies worldwide originates in Canada, with pirates there on pace to illegally produce 150 films this year, more than double the country’s 2005 output, according to the Motion Picture Assn. of America.

Read the full L.A. Times story

. (registration required)