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.
Twitter claims this was an “unintentional,” “inadvertent” mistake. But whether this was avarice or incompetence on Twitter’s part, the result confirms some users’ worst fears: that taking advantage of a bread-and-butter security measure could expose them to privacy violations. Twitter’s abuse of phone numbers for ad tracking threatens to undermine people’s trust in the critical protections that two-factor authentication offers.
