Massive SolarWinds Hack Prompts Calls for U.S. Law Requiring Cyber Breach Reporting A bipartisan group of senators on Tuesday recommended that the U.S. consider requiring companies to disclose when they have been hacked. At the first public hearing before Congress since a massive cyber-attack by suspected Russian hackers was disclosed in December, Senate Intelligence Committee Chairman Mark Warner, a Democrat, was joined by the vice chairman of the committee, Republican Senator Marco Rubio, in calling for the measure. Several others, including Senator Angus King, an independent, also voiced their support, as did several of the tech executives who were testifying.