Enlarge / Elon Musk speaks at the 68th International Astronautical Congress 2017 in Adelaide on September 29, 2017. (credit: PETER PARKS/AFP/Getty Images) Elon Musk's lawyers have fired back at the Securities and Exchange Commission, arguing that the Tesla CEO did not violate the terms of his September settlement with the agency—and that the agency's attempt to gag Musk violates the First Amendment.