The Internet social networking site Facebook agreed to Canada's demand it tighten up its privacy policy, a government official said in Ottawa Thursday.

At a news conference, federal Privacy Commissioner Jenniffer Stoddart said the company's decision to cooperate was "hugely significant" and affected users worldwide.

"Facebook has 12 million users in Canada alone -- that is about a third of our population -- and well more than 200 million users of Facebook worldwide," Stoddart said. "All those users will have a far clearer view of how they perceive information is being shared once Facebook implements our recommendations. They will also have far more control over what they are sharing and with whom."

Among the changes Facebook agreed to make was the physical deletion of personal data after a user deactivates an account or dies and another that would give users more control over which information third-party companies can access from their accounts, a release from the commission said.

Facebook said in a statement the changes "will require significant time and resources," and can't be implemented immediately.

Meanwhile, Stoddart cautioned the end responsibility lies with online users.

"Users must constantly bear in mind that once something is online, it's there for eternity," she said.