SAN FRANCISCO: Concern about Facebook Inc's respect for data privacy is widening to include the information it collects about non-users after Chief Executive Mark Zuckerberg said the world's largest social network tracks people whether they have accounts or not.
Privacy concerns have swamped Facebook since it acknowledged last month that information about millions of users wrongly ended up in the hands of political consultancy Cambridge Analytica, a firm that has counted US President Donald Trump's 2016 electoral campaign among its clients.
Zuckerberg said on Wednesday under questioning by US Representative Ben Luján that, for security reasons, Facebook also collects "data of people who have not signed up for Facebook."
Lawmakers and privacy advocates immediately protested the practice, with many saying Facebook needed to develop a way for non-users to find out what the company knows about them.
"We've got to fix that," Representative Luján, a Democrat, told Zuckerberg, calling for such disclosure, a move that would have unclear effects on the company's ability to target ads.
Zuckerberg did not respond. On Friday Facebook said it had no plans to build such a tool. Critics said that Zuckerberg had not said enough about the extent and use of the data.