Silicon Valley is dealing with ongoing scrutiny over its role in helping stop the spread of fakes news. Alphabet's (GOOGL) - Get Report Google unit and Facebook (FB) - Get Report hold the key to this problem, even though they aren't claiming responsibility, Recode executive editor Kara Swisher said on CNBC's "Squawk Alley" on Friday morning. 

Her comments come after a man fired a rifle into the restaurant Comet Ping Pong in Washington, D.C., earlier this week, after reading a false news story that said the pizza place was the center of a child sex trafficking ring. 

"I feel like Silicon Valley is still 12 years old and they act like they aren't powerful, that they don't have huge businesses, that they just can't fix it because it's super, super duper hard," Swisher said. "Well they've been part of creating this mess and they should absolutely be part of fixing it."

While people have been stumped by fake stories throughout history, the "power and impact" of fake stories is "so far beyond the old days that it's dangerous," she claimed. 

Both Facebook and Google are pretending they aren't media companies in some way, yet they are where everyone gets their news nowadays, Swisher pointed out. They may not be creating news like the New York Times, but they are distributing it. "They're an important part of selecting what gets seen by people," she explained. 

On the other hand, video sharing and messaging app Snapchat has taken charge by picking its publishers and what people can see on its platform, she noted. "Why not start to think about that?" 

Silicon Valley's arguments to abrogate responsibility in this area include that fake news doesn't have an impact and that it's a grey area. The second argument might be valid, but Silicon Valley has smart people, she said. 

"These are smart people who handle it in advertising, when it suits their business needs, and they should be able to figure this out now. Together, I don't know how they do it, but they should be able to," Swisher claimed. 

"Does it necessarily mean an impact on MAUs, timeline engagement, stickiness. Those are things that might be material to an investor," CNBC's Carl Quintanilla said.  

"Absolutely. But at the same time, do you want to create a cesspool?" Swisher asked. "Is that what you want for your business? I mean that's the problem. A lot of these stories create a really bad user experience. That's the thing I would like to focus on because it's the only thing they seem to hear." 

Twitter (TWTR) - Get Report makes you feel a little "icky" a lot of times, but Facebook used to never do that, Swisher said. "Now I feel icky on Facebook," she said. 

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