Oct 5 (Reuters) - Facebook (FB.O) whistleblower Frances Haugen testified before the U.S. Congress on Tuesday, telling lawmakers the social media giant knew its apps were harming the mental health of some young users. Here are some comments from the committee hearing: FRANCES HAUGEN, FACEBOOK WHISTLEBLOWER "I"m here today because I believe Facebook"s products harm children, stoke division and weaken our democracy." "There is no one currently holding Mark (Zuckerberg, the Facebook chief executive) to account. The buck stops with Mark." "Yesterday we saw Facebook taken off the internet. I don"t know why it went down, but I know that for more than five hours, Facebook wasn"t used to deepen divides, destabilize democracies and make young girls and women feel bad about their bodies." "The company"s leadership knows how to make Facebook and Instagram safer, but won"t make the necessary changes because they put their astronomical profits before people." U.S. SENATOR DAN SULLIVAN, REPUBLICAN FROM ALASKA "I think we"re going to look back 20 years from now and all of us are going to be like "what the hell were we thinking" when we recognize the damage that it (social media) has done to a generation." U.S. SENATOR EDWARD MARKEY, DEMOCRAT FROM MASSACHUSETTS "Your (Facebook"s) time of invading our privacy and preying on children is over. Congress will be taking action." KEVIN MCALISTER, FACEBOOK SPOKESPERSON, IN AN EMAIL "The very existence of internal research on tough and complex issues is being recast as an example that Facebook isn’t living up to its responsibilities. The opposite is true: this research is more proof that we invest heavily so our teams can improve our apps and the resources we provide." U.S. SENATOR AMY KLOBUCHAR, DEMOCRAT FROM MINNESOTA "When they allowed 99% of violent content to remain unchecked on their platform including the lead-up to the Jan. 6 insurrection, what did they do? Now we know Mark Zuckerberg was going sailing." U.S. SENATOR ROGER WICKER, REPUBLICAN FROM MISSISSIPPI "Children of America are hooked on their product. There is cynical knowledge on behalf of these Big Tech companies that this is true." U.S. SENATOR MARSHA BLACKBURN, REPUBLICAN FROM TENNESSEE "The research was Facebook"s internal research. So they knew what they were doing, they knew where the violations were and they know they are guilty." "Facebook is not interested in making significant changes to improve kids" safety on their platforms, at least not when that would result in losing eyeballs on posts or decreasing their ad revenues." U.S. SENATOR RICHARD BLUMENTHAL, DEMOCRAT FROM CONNECTICUT "The damage to self-interest and self-worth inflicted by Facebook today will haunt a generation." "Big Tech now faces the Big Tobacco jaw-dropping moment of truth." "Our children are the ones who are victims. Teens today looking in the mirror feel doubt and insecurity. Mark Zuckerberg ought to be looking at himself in the mirror."