https://www.techdirt.com/articles/20180823/06590240492/facebooks-privacy-protecting-vpn-booted-apple-store-snooping-too-much.shtml

Back in February we noted how Facebook had launched a new security tool the company promised would "help keep you and your data safe when you browse and share information on the web." The product was effectively just a VPN; largely a repackaged version of the Onavo platform the company acquired back in 2013. We also noted how some reports were quick to point out that instead of making Facebook users' data more private and secure, Facebook used the VPN to track users around the internet -- specifically what users were doing when they visited other social media platforms.

From a report in the Wall Street Journal just about a year ago: