Keith Gill, who goes by the nickname Roaring Kitty, has been sued for allegedly orchestrating a "pump and dump" scheme involving GameStop Corp.'s stock. Gill, who became famous for driving the "meme stock" frenzy of 2021, posted about GameStop again on social media X in May. In a proposed class-action lawsuit filed Friday in federal court in Brooklyn, New York, GameStop shareholder Martin Radev alleges that Gill tried to manipulate the stock to his advantage. The lawsuit alleges that Gill bought 120,000 call options on the company before he began posting about GameStop in May. The stock had been trading around $17 just before Gill posted, before surging to $48.75 on May 14.