Facebook did not notify the more than 530 million users whose details were obtained through the misuse of a feature before 2019 and recently made public in a database, and does not currently have plans to do so, a company spokesman said this week.
Business Insider reported last week that phone numbers and other details from user profiles were available in a public database. Facebook said in a blog post that "malicious actors" had obtained the data prior to September 2019 by "scraping" profiles using a vulnerability in the platform's tool for synching contacts.
Users can use the the Have I Been Pwned online tool, which is independent of Facebook, to check if their numbers or emails were compromised.
But the Facebook spokesman said the social media company was not confident it had full visibility on which users would need to be notified. He said it also took into account that users could not fix the issue and that the data was publicly available in deciding not to notify users. Facebook has said it plugged the hole after identifying the problem at the time.
The scraped information did not include financial information, health information or passwords, Facebook said. However, the collated data could provide valuable information for hacks or other abuses.
Facebook, which has long been under scrutiny over how it handles user privacy, in 2019 reached a landmark settlement with the US Federal Trade Commission over its investigation into allegations the company misused user data.
Ireland's Data Protection Commission, the European Union's lead regulator for Facebook, said on Tuesday (local time) it had contacted the company about the data leak. It said it received "no proactive communication from Facebook" but was now in contact.
The July 2019 FTC settlement requires Facebook to report details about unauthorised access to data on 500 or more users within 30 days of confirming an incident.
The Facebook spokesman declined to comment on the company's conversations with regulators but said it was in contact to answer their questions.