Twitter admits it used two-factor phone numbers and emails for serving targeted ads

Twitter has said it may have “inadvertently” used phone numbers and email addresses that users provided to secure their accounts to serve targeted advertisements. In a disclosure Tuesday, the social media giant said it did not know how many users were impacted. The issue stemmed from the company’s tailored audiences program, which allows companies to target advertisements against their own marketing lists, such as phone numbers and email addresses. But Twitter found that when advertisers uploaded their marketing lists, it matched Twitter users to the phone numbers and email addresses users submitted to set up two-factor authentication on their account. The issue was addressed as of September 17, the disclosure said. Twitter finds itself in the same boat as Facebook, which …