I think the closest thing would be discrimination lawsuits?

Like, let’s say that a black guy runs a transport company in a rural, very racist state. He receives positive reviews for his service, but none of the 5 or so clients in his area will do business with him - meanwhile sub clients of those businesses actually wish he was the one working with them. He might have a case to say these business owners colluded to deny him a market in an unfair way - and that it was not just based around their “right to choose who they do business with”.

Of course, the history of Twitter has far, far more personal blame to it than the story of a black business owner facing racial discrimination. Just thinking about what general angle his lawyers may try in court.