美国有线新闻 CNN 脸谱网和推特高管出席美国会听证会 承诺打击假新闻（在线收听）

You probably used Google, Facebook and/or Twitter in the last 24 hours. These companies executives were recently asked to testify before the U.S. Senate Intelligence Committee. This part of Congress has the job of overseeing the government's intelligence work and programs and one thing it's investigating is how people or organizations in other countries are using social media to influence U.S. politics. The American Intelligence community has repeatedly accused Russia of trying to influence the 2016 U.S. Presidential election.

Russia has repeatedly denied doing it. And last year CNN investigated how people in the small European country of Macedonia used websites to spread fake news, unproven or just made up stories and make a relative fortune from the advertising. Yesterday's hearing on Capital Hill was the third time in 12 months that someone from a major technology company appeared before the Senate Committee. Not everyone who was invited sh???owed up.

Facebook sent it's Chief Operating Officer Sheryl Sandberg. Twitter's Chief Executive Officer Jack Dorsey appeared but Google refused to send a high profile executive.

It offered it's Senior Vice-President of Global Affairs but Senators said that wasn't senior enough so Google's place only had an empty chair.

Still, the hearing went on. Sandberg and Dorsey discussed what their companies have done to prevent false information from being spread on Facebook and Twitter to make it clearer where their political ads come from and to say their companies are working more closely together to share information on foreign threats. But they both also regretted that their platforms have been used inappropriately in the past and that they hadn't been prepared, at least at first, to deal with it.