Some of Twitter’s source code was leaked and published to GitHub lol. Twitter sent a copyright infringement notice to GitHub which took down the repo. “It was unclear how long the leaked code had been online, but it appeared to have been public for at least several months.” https://web.archive.org/web/20230327012334/https://www.nytimes.com/2023/03/26/technology/twitter-source-code-leak.html