Paul Graham, a well-known entrepreneur and investor, has announced that he is leaving Twitter due to the platform's policies and has created a new profile on Mastodon. Graham's decision comes after Twitter's new owner, Elon Musk, implemented changes to the platform's moderation policies. Musk's actions have been met with criticism from some users, who feel that the platform is becoming a right-wing echo chamber. Graham's departure is seen as a significant loss for Twitter, as he was a prominent and influential user.