Twitter used phone numbers gathered for account security to sell adverts

Twitter “inadvertently” used phone numbers and email addresses its users provided for account security purposes to target ads, the company said Tuesday.

In July, the Federal Trade Commission (FTC) said Facebook had broken the law when it engaged in a similar practice. The FTC fined Facebook $5 billion for that and a litany of other instances where it mishandled user data.

Twitter users are asked to provide information like their phone number to help secure their account through services such as two-factor authentication.

Phone numbers provided to Twitter for the purpose of two-factor authentication were recently exposed as a hacking vulnerability as well. A hacker or hackers were able to tweet from the account of CEO Jack Dorsey by convincing Twitter’s systems that they had his phone and were texting the tweets to his account.