"The sharing of information does directly affect privacy, so that's where my concerns would lie," Daniel Therrien told the House privacy committee on Thursday afternoon.
He noted that, while the Canadian Security Intelligence Service (CSIS) is subject to independent oversight through the Security Intelligence Review Committee, that isn't the case for all of the federal organizations with which it would be authorized to share information under the proposed changes to the law.
"Judge O'Connor in the Arar affair pointed out that there are shortcomings in independent oversight, and recommendations were put forward to the effect that government agencies involved in intelligence should be the subject of oversight in the same way as CSIS is."
Practically speaking, he said, the bill before the House right now deals with CSIS's mandate, and "indirectly," the sharing of information by the same.
"That information can be shared with a certain number of federal organizations, and some do not fall under independent oversight — for example, Canada Border Services Agency — and that is a concern."
In response to questions from opposition members, Therrien also confirmed he had wanted to testify before the House public safety committee during its study of the bill, but his offer was rejected.
Cyberbullying bill could face legal challenge
During his hour-long appearance, Therrien reiterated his critique of another contentious piece of legislation, C-13, the "cyberbullying" bill, which is currently before the Senate and expected to become law before MPs head home for the holidays.
Until a landmark decision handed down by the Supreme Court last June, "it was not at all clear whether information that Canadians were putting on the internet was private," Therrien explained in response to a question from New Democrat MP Charmaine Borg.
He described that ruling as "a big step forward in terms of privacy."
"[It] states clearly that when personal information is connected to activities of individuals, that information is constitutionally protected," he noted.
He predicted that, if passed without amendments, the bill could face a Charter challenge.
"I think there may be some uncertainty for the courts … and I think the courts eventually may determine that there are unconstitutional aspects," he told the committee.
"In the end, I think Canadians may be in the dark for a while until courts have ruled on those aspects."