While the majority of users affected by the Cambridge Analytica fiasco were based in the US, Australia was the 10th worst country hit, according to.
It's the latest revelation in what has been a tough month for Facebook, after it was revealed data from millions of Facebook users was, a digital consultancy with ties to the Trump presidential campaign.
The original number of accounts was estimated at 50 million, but Facebook revised this figure upward toon Thursday. Of these, Facebook estimated 300,000 accounts belonged to Australians.
As a result, the Office of the Australian Information Commissioner (OAIC) has confirmed it will conduct an investigation to determine whether Facebook breached Australia's Privacy Act.
In a statement, acting Australian Information Commissioner and acting Privacy Commissioner Angelene Falk said her office will confer with international authorities as part of the investigation.
"All organisations that are covered by the Privacy Act have obligations in relation to the personal information that they hold," Falk said in a statement.
"This includes taking reasonable steps to ensure that personal information is held securely, and ensuring that customers are adequately notified about the collection and handling of their personal information."
In a statement provided to CNET, Facebook said it would work with the OAIC throughout the investigation.
"We are strongly committed to protecting people's information, and we will be fully responsive to OAIC's investigation," a Facebook spokesperson said. "We've recently made significant updates to make our, restrict data access on Facebook, and make our Terms and Data Policy clearer. Overall, we believe these changes will better protect people's information -- we know we have more work to do, and we'll keep our community updated as we make more changes."
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