Twitter’s former head of security Peiter “Mudge” Zatko on Tuesday told the US Senate Judiciary Committee that the social media company’s lax data handling and inability to present problems to its board of directors threaten the privacy, security, and democracy for Americans.

Zatko appeared before Senate lawmakers to testify about the whistleblower report he submitted late last month detailing concerns about the state of cybersecurity at the microblogging outfit. In today’s testimony he claimed Twitter management was lying to its board, and to regulators both foreign and domestic.

“Twitter’s security failures threaten national security, compromise the privacy and security of users, and at times threaten the very continued existence of the Company,” said Zatko in prepared remarks [PDF].