SMS Two-Factor Authentication is becoming a Twitter Blue exclusive feature.

Twitter’s decision to disable SMS-based two-factor authentication for all non-Twitter Blue subscribers has raised security and accessibility concerns. As a result of this change, the most commonly used form of authentication will now be available only to those willing to pay Twitter $8 per month, potentially leading to more account hacks and problems with people losing access. The rationale behind Twitter’s decision is to lessen the impact of spammers and scammers in the app. Twitter Blue may be too expensive for users in developing economies, which account for a sizable portion of Twitter’s user base. Users may find the new requirement for authentication apps or security keys inconvenient. It remains to be seen whether this move will encourage more people to subscribe to Twitter Blue, but anyone who values their Twitter account should reconsider their security options.