you give a tech company your personal information in order to use two-factor authentication, and later find out that they were using that security information for targeted advertising. Twitter also does that. They has been taking email addresses and phone numbers that users provided for “safety and security purposes” like two-factor authentication, and using them for its ad tracking systems, known as Tailored Audiences and Partner Audiences. Twitter claims this was an “unintentional,” “inadvertent” mistake.
— source wolfstreet.com | Oct 10, 2019