Tweeted By @random_walker
Facebook asks users to add their phone numbers for 2-factor authentication, then misuses that info to target ads. Researchers at Northeastern uncovered this by signing up as an advertiser and finding many clever tricks to reverse-engineer FB's targeting. https://t.co/EDvVJmkDIW pic.twitter.com/au5qZEGZrx
— Arvind Narayanan (@random_walker) July 18, 2019