Twitter has announced that it unintentionally used some peoples personal information in some of its adverts.
The adverts were ones that were for Tailored Audiences and used peoples email addresses, you can see what the company had to say below.
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.
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). Partner Audiences allows advertisers to use the same Tailored Audiences features to target ads to audiences provided by third-party partners. When an advertiser uploaded their marketing list, we may have matched people on Twitter to their list based on the email or phone number the Twitter account holder provided for safety and security purposes. This was an error and we apologize.
You can find out more information about this over at Twitter at the link below, if you think you have been affected then you can contact Twitter.