The practice of "shadow bans," often referred to as "visibility filtering" internally, is detailed in a recent investigation. Twitter's ‘secret blacklists’ have been exposed.
According to internal correspondence and interviews with several high-level corporate sources, Twitter has developed a number of barriers and tools for moderators to prevent particular tweets and topics from trending or restrict the exposure of entire accounts without users' knowledge.
According to journalist Bari Weiss, who posted the second installment of the so-called "Twitter Files" in a protracted thread on Thursday night, despite frequent public assurances by leading Twitter officials that the company does not "shadow ban" users, especially not "based on political viewpoints or ideology," the procedure did exist underneath the euphemism of "visibility filtering".
“Think about visibility filtering as being a way for us to suppress what people see to different levels. It’s a very powerful tool,” ...