Obama addresses disinformation in the digital age at Stanford University

In the war on disinformation, former President Barack Obama says it's time Silicon Valley, legislators, and the public took action.

"Now is the time to pick a side," he said. Speaking at Stanford University, Obama addressed the risks posed by an unregulated and unchanged version of social media: the kind where lies about vaccines and election results go unchallenged.

"Over time we lose our capacity to distinguish between fact, opinion, and wholesale fiction, or maybe we just stop caring," said Obama.

He admits he benefited from social media on his path to the presidency and wishes he had seen the warning signs sooner.

"What does still nag at me was my failure to appreciate at the time just how susceptible we had become to lies and conspiracy theories," he said.

Now he fears it will weaken democracy. And so he's calling for action, both internally from Silicon Valley companies and also from legislators.

"This is an opportunity. It's a chance we should welcome for governments to take on a big important problem and prove democracy and innovation can coexist. It's a chance for companies to do the right thing. You'll still make money, but you'll feel better," Obama said.

Experts say in an era where people can't seem to agree on what is true, agreeing on a course of action may be challenging.

But they say individuals can help stop the spread of questionable information.

"Why does false information, sensational information spread. It is because we do click that share button right. We feel like this really made me mad and I'm going to share it with all my friends so they can be mad too. We can resist that temptation," said Renee Diresta with the Stanford Internet Observatory.

And President Obama hopes this is just the beginning, because he said the risk of inaction is simply too great.

"Do we allow our democracy to whither or do we make it better? That's the choice we face. And it's a choice worth embracing," he said.