US Congress grills Facebook, Twitter over foreign bids to tilt politics

Facebook, Twitter and other technology firms have been on the defensive for many months over political influence activity on their sites as well as concerns over user privacy.

Executives from Facebook Inc and Twitter Inc faced threats of legislative action from skeptical US lawmakers on Wednesday over what many members of Congress see as a failure to combat foreign efforts to influence US politics.

Shares of social media companies fell after the start of the hearing when Senator Mark Warner, the committee's Democratic vice chairman, said the companies and Alphabet Inc's Google have not done enough to slow the spread of disinformation, and threatened "action." Facebook Chief Operating Officer Sheryl Sandberg, who testified alongside Twitter Chief Executive Jack Dorsey, acknowledged that the company was too slow to respond