Federal regulators announced charges against Twitter on Wednesday, saying the social media platform deceptively used personal account data for targeted advertising.
The Federal Trade Commission has fined Twitter $150 million.
The FTC said in a statement that millions of Twitter users provided phone numbers or email addresses from 2014 to 2019 after the company told them the information would be used to help secure their accounts.
Twitter then used that information for targeted advertising, the FTC alleged, allowing advertisers to reach specific consumers by matching the information with data they already had or had obtained from data brokers.
“This practice affected more than 140 million Twitter users, while boosting Twitter’s primary source of revenue,” FTC Chair Lina Khan said in a statement.
A representative for Twitter referred a request for comment to a company blog post in which Chief Privacy Officer Damien Kieran said that "some email addresses and phone numbers provided for account security purposes may have been inadvertently used for advertising" and that the issue had been addressed as of Sept. 17, 2019.
"Keeping data secure and respecting privacy is something we take extremely seriously, and we have cooperated with the FTC every step of the way," Kieran wrote. "In reaching this settlement, we have paid a $150M USD penalty, and we have aligned with the agency on operational updates and program enhancements to ensure that people’s personal data remains secure and their privacy protected."
Advertising accounts for the bulk of Twitter's revenue. The exact number of active users on the platform has become a flashpoint in the social media company's sale to Elon Musk, who accused the company of obfuscating how many automated accounts, or "bots," are on the site.
Musk also wants to cut down on the amount of advertising the site uses in general, hoping to create paid subscription products, instead.