Twitter Apologizes for Using Your Phone Number for Advertising

"This was an error and we apologize".

In that case, the Federal Trade Commission alleged Facebook deceived users because it "did not disclose, or did not adequately disclose" that phone numbers provided through its security tool for the objective of two-factor authentication "also would be used by Facebook to target advertisements to those users".

Twitter Inc said on Tuesday (Oct 8) email addresses and phone numbers uploaded by users to meet its security requirements may have been "inadvertently" used for advertising purposes.

The information has been shared publicly since Twitter does not know the exact number of people that were affected in this incident and the company wanted to make everyone aware of what happened. "No personal data was ever shared externally with our partners or any other third parties", the mea cupa reads.

"Tailored Audiences is a version of an industry-standard product that allows advertisers to target ads to customers based on the advertiser's own marketing lists (e.g. email addresses or phone numbers they have compiled)".

"We can not say with certainty how many people were impacted by this, but in an effort to be transparent, we wanted to make everyone aware", Twitter said.

Facebook also agreed not to use phone numbers given for security purposes to advertise to people.

That information is supposed to be used exclusively for account protection purposes, but Twitter said advertisers were able to tap the phone numbers to target commercials, through the company's "Tailored Audiences" and "Partner Audiences advertising system".

Twitter now joins Facebook, which was caught doing the exact same thing a year ago by a group of academics from Northeastern University and Princeton University.

Users, however, do not look to be happy with either the mishap or the way Twitter is handling the disclosure.

Later on, Facebook used the phone numbers its users added for two-factor authentication as an additional targeting vector for various advertisers using its platform to deliver targeted ads.