idea. >> reporter: others disagree. these fake sites are easy to set up and profitable for the creators. every time we click and share, they make more money. but we are worse off. now facebook and google are banning fake sites from making money off their ad networks. it's a first effort to choke off some of the revenue. the bigger challenge, providing more b.s. detection tools without threatening free speech. >> suddenly they have these, i think, social societal duties to help us not be faked out all the time. and yet i don't want the terms of service of one company or two or three companies to have more influence than the first amendment. >> reporter: the root problem is that some people want to believe the lies. that's why the responsibility isn't just facebook or google or twitter. we all have to get a little smarter about what we share.