Facebook Chief Operating Officer Sheryl Sandberg acknowledged that the social network will likely be subject to regulation in the wake of the Cambridge Analytica scandal in which millions of users’ personal information was accessed without their permission.

“It’s not a question of ‘if regulation’ it’s a question of what type,” Sandberg said in an interview today with CNBC’s Julia Boorstin. “We are not even waiting around for regulation.”

Sandberg began the interview accepting responsibility for what she called a “huge breach of trust” and apologizing to Facebook’s users, who rely upon the social network to safeguard their data, for letting them down. She reiterated the company’s pledge to conduct an audit of third-party apps and crack down on misuse.

“This is about trust,” Sandberg said, “and earning the trust of the people who use our service is the most important thing we do, and we are very committed to earning it.”

Boorstin asked why, despite earlier reports of Russian propagandists using Facebook to spread misinformation, these latest revelations are provoking such fierce backlash among investors and users, some of whom have mounted a #DeleteFacebook social media campaign.

“This goes to the core of our service and to data,” Sandberg said, noting Facebook’s earlier efforts to restrict access to user data. “But that wasn’t enough. We need to do more to verify and notify.”

Venture Capitalist Roger McNamee, an early Facebook investor, wondered aloud on CBNC whether Facebook’s business model – which relies on targeted advertising — is at odds with promises of privacy.

“The most important thing we can do for running this company is protect people’s data,” Sandberg said.

Boorstin asked if Facebook can “guarantee” there won’t be other abuses by third-party app developers like Cambridge University’s Aleksandr Kogan, whose personality test harvested user profile information of more than 50 million Americans that was later used by Cambridge Analytica.

“There will always be bad actors who have tried to use the platform, who will use the platform,” Sandberg said. “We are now going back and we are going to investigate apps and, if we find anything, we’re gonna tell people their data was potentially misused.”

Boorstin asked Sandberg whether stricter regulation might harm Facebook’s business, which already lost $50 billion in valuation in the days since The New York Times and The Guardian in the U.K. reported the data leak.

“We run this company for the protection of our community and our people,” Sandberg said. “We’re not looking at these tradeoffs like, ‘Oh, its going to hurt our business.'”

Asked if Facebook would welcome regulation, at a time when legislators on Capitol Hill and in the Europe appear to be clamoring for greater oversight, Sandberg responded, “We’re open to regulation. We will work with lawmakers all over the world.”