The potential FTC fine comes after Twitter last year acknowledged that user emails and phone numbers were being used for targeted advertising between 2013 and 2019. Twitter did not disclose exactly when they discovered what was happening but said that as of Sept. 17, the issue has been addressed. Twitter estimates that the range of probable loss in this matter is $150.0 million to $250 million. In July 2019, the FTC slapped a $5 billion fine on Facebook for privacy violations following its Cambridge Analytica incident.
Source: https://threatpost.com/twitter-could-face-250m-ftc-fine-over-improper-data-use/158014/