Canada's privacy commissioner sent a letter warning the federal government that its plans to reform Canada's copyright laws should not come at the expense of personal privacy.

In a letter published on her office's website Friday and directed to Industry Minister Jim Prentice and Heritage Minister Josée Verner, Jennifer Stoddart warned that any changes to the Copyright Act should not authorize the use of digital rights management technologies that allow companies to collect and retain information without the user's consent.

"While I am not concerned with copyright law in itself, and I certainly understand the need to update the Copyright Act, I am concerned about possible changes to the Act authorizing the use of technical mechanisms to prevent copyright infringement that could have a negative impact on the privacy rights of Canadians," she wrote.

"Technologies that automatically collect personal information about individuals without their knowledge or consent violate the fair information principles that are central to PIPEDA [Canada's Personal Information Protection and Electronic Documents Act] and most other privacy legislation," she wrote.

Stoddart's letter comes as the federal government continues to work on legislation to reform the act.

The bill — which would have made such activities as the time-shifting of television shows, file-sharing of music and video, and copying files to CDs or MP3 players illegal — was scheduled to be introduced in December.

At an open house in his Calgary constituency in December, Prentice had argued that such legislation was necessary to bring Canada in line with its obligations to the World Intellectual Property Organization, which it signed on to in 1997.

But the government pushed back the planned introduction of the legislation after more than 50 angry protesters showed up to question him at the meeting, and an online group formed to oppose it on social networking site Facebook.

The group, which now has close to 40,000 Facebook users on it, was started by University of Ottawa professor Michael Geist, a chief opponent of the legislation.

Geist, writing in his blog on Friday, said, "Stoddart’s public letter provides an important reminder that it is more than just copyright law that hangs in the balance as the government's plans could ultimately place Canadians' privacy at risk."