Twitter apologized to have used phone numbers and email addresses,
“We recently discovered that when you provided an email address or phone number for safety or security purposes (for example, two-factor authentication) this data may have inadvertently been used for advertising purposes, specifically in our Tailored Audiences and Partner Audiences advertising system.” reads a post published by Twitter.
At the time of writing it is unclear the number of impacted Twitter users.
The company attempted to downplay the severity of the privacy incident highlighting that none of the user data
The Twitter Tailored Audiences product allows advertisers to target ads to customers based on the advertiser’s own marketing lists that includes info such as email addresses or phone numbers. Partner Audiences allows advertisers to use the same Tailored Audiences features to target ads to audiences provided by third-party partners.
Twitter admitted that when an advertiser uploaded their marketing list, its staff may have matched the information included in these lists with data provided by its users to protect their accounts.
The root cause of the problem was addressed in September 17, 2019.
“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. No personal data was ever shared externally with our partners or any other third parties.” added Twitter.
“We’re very sorry this happened and are taking steps to make sure we don’t make a mistake like this again,”