Twitter Inc. said it was sorry Tuesday after admitting that it used people’s phone numbers and email addresses for advertising purposes even though that information should have only been used for two-factor identification.

In a blog post, the company said the data was inadvertently used in the “Tailored Audiences” and “Partner Audiences” systems. Companies can send Twitter lists of emails and phones that they have created themselves and then target them with ads on the platform, but it seems in this case Twitter matched them with private security information.

“We cannot say with certainty how many people were impacted by this, but in an effort to be transparent, we wanted to make everyone aware,” said Twitter. “No personal data was ever shared externally with our partners or any other third parties.” The company added that as of Sept. 17 the issue was fixed.

This is not the first time such a thing has happened on a social media platform. In 2018, Facebook Inc. owned up to using people’s personal security information for advertising purposes. Twitter might hope it doesn’t come under the same scrutiny as Facebook, since the latter company was fined $5 billion this year for lax data controls.

“We’re very sorry this happened and are taking steps to make sure we don’t make a mistake like this again,” Twitter said in the post.

Image: Esther Vargas/Flickr