At various times, most social media platforms have received criticism for alleged failure to prevent distribution of copyright-infringing content. Few, however, have been threatened with widespread blocking more often than Telegram. In a row that seemed ready to boil over last year, Telegram was given an ultimatum by the Malaysian government; come to the negotiating table or face the consequences. A Malaysian minister now says that Telegram is ready to fight piracy.
Not sure why you’re citing US law when we’re discussing foreign govts. Also the obvious thing signal can do, that most complainants would probably expect as a minimum, is banning their accounts and closing the group.