Therrien also warned against the lower standard of proof provided for in the bill, C-13, and said he disagrees with the government's assertion that the information intended to be sought isn't sensitive.
The bill would make it illegal for anyone to post or transmit an "intimate image" of another individual without that person’s consent. But other measures included in the bill would give police easier access to the metadata that internet service providers and phone companies keep on every call and email from their customers. Those measures had been in a previous online surveillance bill, C-30, that created such a backlash the government killed it.
Therrien urged parliamentarians to "build into Bill C-13 the necessary reporting mechanisms that would allow Canadians to hold government to account" for how the "significant new powers" would be used.
It was Therrien's first committee appearance on C-13 since a June Supreme Court decision that affirmed Canadians have a right to privacy online.
The Spencer decision barred internet service providers from voluntarily disclosing the names, addresses and phone numbers of their customers to law enforcement officials in response to an informal request — something internet service providers, or ISPs, have been doing hundreds of thousands of times a year.
Therrien said he's got a number of concerns about the bill, which the government has defended by referring to the need to protect children and teens from cyberbullying.
But, he said, "it is important to remember that these new investigative tools would sweep up vast amounts of personal information by an open-ended group of 'public officers' for a wide range of much less compelling purposes than the fight against cyberbullying."
Story continues below
Judicial scrutiny, reporting needed
Therrien suggested the government hasn't properly considered the impact of the court's decision in confirming privacy rights.
"Despite the judgment in Spencer, I see, again important players in the debate, government, telecommunication companies, federal departments, making statements that do not give me a whole lot of confidence on what impact Spencer will actually have. They seem to give a very narrow interpretation to Spencer," he said.
Justice Minister Peter MacKay has said the ruling doesn't affect C-13.
Therrien seemed like an unlikely critic of increased powers for law enforcement after spending most of his career as a government lawyer in areas like public safety and corrections. He became privacy commissioner last June.
In his office's written submission to the committee, Therrien says the new bill will lead to "a marked difference in privacy protection."
"The potential level of government intrusion must be matched by commensurate judicial scrutiny and an appropriate legal standard for authorization. There should be evidence of a higher probability of wrongdoing before information about individuals’ private communications or their digital activities are compelled," he wrote.
"Downgrading to a 'reasonable suspicion' standard should be a necessary and proportionate response to a demonstrated problem, and in our view, a more compelling case for the use of a reduced legal threshold must be presented and thoroughly examined."
An official from his office told the committee that a reporting requirement or a requirement for organizations to report to a client after they'd provided that client's information to law enforcement officials would help keep the process accountable.