Canada's privacy commissioner has warned in her annual report that personal freedoms in the country are being eroded by the "war on terror".
Canadian citizen Maher Arar was deported to Syria by the US during an anti-terror clampdown
Jennifer Stoddart told parliament that as agencies collected more information on people, there were higher risks that travellers would be treated unfairly.
The kinds of security measures taken by the US came in for particular scrutiny.
Better solutions might lie in using existing information more effectively, she added.
Ms Stoddart said recent US pressure on the Canadian government to share information with US authorities about all people travelling to Canada meant there was more of a possibility that people would be wrongly singled out and treated unfairly.
She warned that mistakes had already been made, possibly referring to the high-profile case of Arab-Canadian Maher Arar who was was deported to Syria by the US.
The report also raises concerns about the growing use of private companies by government national security agencies to collect personal information about individuals.
The province of British Columbia has already launched an inquiry into the issue.
This was prompted by fears that a US healthcare company could have access to personal information about Canadians and then be forced under the American Patriot Act to turn that information over to US agencies such as the FBI.