The concern over Facebook’s use of information escalated after Chief Executive Mark Zuckerberg said the world’s largest social network tracks people whether they have accounts or not.
Privacy concerns have dogged the social media giant since it revealed last month that information about millions of users ended up in the hands of political consultancy Cambridge Analytica, a firm that has counted U.S. President Donald Trump’s 2016 electoral campaign among its clients.
Zuckerberg acknowledged on Wednesday under questioning by U.S. Representative Ben Luján that, for security reasons, Facebook also collects “data of people who have not signed up for Facebook.”
Lawmakers and other privacy advocates protested this practice and demanded that Facebook 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 certainly have effects on the company’s ability to target ads. Zuckerberg did not respond, and on Friday Facebook said it had no plans to build such a tool.
Critics want to hear more from Zuckerberg about the extent and use of the data. “It’s not clear what Facebook is doing with that information,” said Chris Calabrese, vice president for policy at the Center for Democracy & Technology, a Washington advocacy group.
Facebook gets some data on non-users from people on its network, such as when a user uploads email addresses of friends. More information comes from “cookies,” small files stored via a browser and used by Facebook and others to track people on the internet, sometimes to target them with ads.
“This kind of data collection is fundamental to how the internet works,” Facebook said in a statement.
When asked if people could opt out, Facebook said, “There are basic things you can do to limit the use of this information for advertising, like using browser or device settings to delete cookies. This would apply to other services beyond Facebook because, as mentioned, it is standard to how the internet works.”
The ACLU is pushing U.S. lawmakers to develop broad privacy legislation including a requirement for consent prior to data collection.