https://www.siliconvalley.com/2019/09/05/twitter-clamps-down-on-tweeting-via-text-messages/

Twitter users who like to tweet directly from their text messaging app will, at least for a while, have to settle for a different way to get their messages out into the world.

Twitter has turned off the text tweeting ability in most of the world after a couple of high-profile accounts were hacked, including the one belonging to CEO Jack Dorsey. The company said Wednesday that it was temporarily suspending the SMS, or text messaging, tweeting function because of “vulnerabilities that need to be addressed by mobile carriers and our reliance on having a linked phone number for two-factor authentication.”