United States lawmakers questioned representatives of Facebook, Twitter and Google over Russian efforts to influence the 2016 presidential election.

　　The U.S. Congress is investigating how Russia used the companies' internet services to spread disinformation during the election. Congress also asked how the companies planned to stop the misuse of their services in the future.

　　Senate Intelligence Chairman Richard Burr of North Carolina spoke to lawyers from the three companies at a hearing on Wednesday. He said media reports suggested that Russian-linked Facebook advertisements "directly influenced the election's outcome."

　　The reports claim Russian government agents spent as much as $100,000 on Facebook advertisements.

　　"You must do better to protect the American people and...all of your users from this kind of manipulation," Burr said.

　　Senator Dianne Feinstein of California argued that social media companies are responsible for the material placed on their websites.

　　Fienstein expressed anger over the reports and suggested that lawmakers may take action.

　　She said, "You've created these platforms, and now they are being misused. And you have to be the ones to do something about it – or we will."

　　Facebook, Instagram and Twitter identified some of the material that has been connected to Russian agents. Democratic Party members on the House Intelligence Committee showed examples of this material during the hearings.

　　The advertisements, videos and tweets covered topics including race, immigration, Islam, and issues of sexual identity.

　　Facebook, Twitter and Google have admitted that agents connected to Russia used false accounts on their sites throughout 2015 and 2016.

　　They used the accounts and other methods to spread false advertisements and messages designed to make people angry. Facebook lawyer Colin Stretch told lawmakers last Wednesday that Russian-backed posts on his company's site reached millions of Americans.

　　Lawyers for all three companies stated that they take the problem seriously and are aggressively fighting it.

　　Sean Edgett, a lawyer for Twitter, repeated a statement he made to the Senate Judiciary Committee one day earlier. He said the company has studied all the posts on its site from September 1 to November 15, 2016. Edgett said Twitter has suspended 2,752 accounts suspected of Russian links.

　　Colin Stretch said that false advertisements "were a very small fraction of the overall content on Facebook.

　　He said, however, that the company was taking measures to improve. "We're hiring more ad reviewers, doubling or more our security engineering efforts, putting in place tighter content restrictions," he said. Stretch added that buyers of political ads would have to provide documentation about themselves.

　　The House Select Committee also met on the issue

　　A few hours after meeting with the Senate Intelligence Committee, the companies' lawyers met with the House Select Committee on Intelligence to discuss the same issue.

　　Republicans on that committee mainly discussed information from the websites showing when the Russian disinformation efforts began.

　　The information showed that these efforts started before the Republican Party nominated Donald Trump as its presidential candidate.

　　Senator James Risch of Idaho said, "This is a whole lot broader than simply the 2016 election.

　　Google's lawyer Kent Walker agreed. He said, "The large majority of the material we saw was socially divisive rather than electoral advocacy."

　　However, some Democrats disagreed. Representative Adam Schiff of California said Russian ads targeted stories about Hillary Clinton's health and legal problems.

　　Some Democrats also accused the technology businesses of being slow to recognize and combat the threat.

　　Senator Mark Warner of Virginia said the big social media companies have a lot of information about Americans. "And the idea that you had no idea that any of this was happening strains my credibility," he said.

　　Both the House and Senate intelligence committees are holding yearlong investigations into Russian interference in the 2016 election. Reports from both are expected at a future date.

　　Members of both parties in the Senate have introduced legislation to deal with the problem. The bills would require internet-based services to confirm and make public the identities of those buying political advertising. U.S. broadcasters are already required to do that.

　　I'm ­Jonathan Evans.

　　Joshua Fatzick, Michael Bowman and Katherine Gypson reported this for VOA News. Pete Musto adapted it for Learning English. Mario Ritter was the editor.

　　How should governments hold internet-based services responsible for the material users post on their sites? Write to us in the Comments Section or on 51VOA.COM.