Facebook co-founder Chris Hughes told CNBC on Tuesday he doesn't think the social media giant has done enough to protect its users' personal data.

The issue over privacy came to the forefront after the research firm Cambridge Analytica was recently accused of improperly accessing the personal user data of as many as 87 million Facebook users.

Hughes said it is now a question of what Facebook and others will do next, and whether that should include government intervention.

"It's not just enough to trust the corporations. I think that there's a role for public policy as well," he told Brian Sullivan on "Closing Bell" from the Milken Institute Global Conference.

He believes public pressure should be kept up on companies to make sure data are secure. At the same time, there should be something like a data privacy bill of rights or some type of "consumer data protection bureau that makes sure that there's the rule of law when it comes to these questions," he said.

Hughes, a Harvard dormmate of Facebook CEO Mark Zuckerberg, was the early spokesperson for the social network. He also worked on the products team.

Hughes left Silicon Valley to help organize the online efforts for Barack Obama's 2008 presidential campaign.

"There is a sense all of these companies have gotten very big very fast. Perhaps too big," said Hughes, now co-chair of The Economic Security Project.

During his congressional testimony in April, Zuckerberg acknowledged it is "inevitable" there will need to be some regulation of social media.

"I also think you have to be careful about what regulation you put in place," the CEO said.

Hughes said while companies can and should innovate, they should also make sure that data is protected and that "people can share in the upside," he said.

"A small group of companies is creating historic level of profits" from that consumer data, he said.

He thinks they can put about 5 percent into a sovereign wealth fund and then cut a dividend check.