Based on the search results, there have been multiple class action lawsuits and legal actions against Coinbase, a prominent cryptocurrency exchange. These lawsuits allege that Coinbase sold unregistered securities and operated as an unregistered broker-dealer. However, it's important to note that a U.S. District Court Judge dismissed a proposed class action lawsuit alleging these claims. The judge found that the plaintiffs' claims contradicted their initial complaint, leading to the dismissal of