Hellthread, also known as Hellrope, refers to a bug or feature in the social networking part of the decentralized protocol Bluesky. The social, frontend part of Bluesky, which resembles Twitter, allows users to reply to skeets made by other users and assemble threads made of many replies from many different people. The hellthread is a reply thread that notifies every single user on it anytime that someone posts anyplace along the thread. At the beginning of its history, it was impossible to mute hellthread notifications.