Mark Zuckerberg has broken his silence on the Cambridge Analytica controversy, reports The Los Angeles Times.

In a statement posted on his Facebook page, Zuckerberg acknowledged his company’s failure to protect its users’ information, while trying to convince his customers they can still trust the social media giant.

“I started Facebook, and at the end of the day I’m responsible for what happens on our platform,” he said. “We have a responsibility to protect your data, and if we can’t then we don’t deserve to serve you.”

The Facebook CEO also announced changes that would prevent third parties from accessing Facebook’s information. Facebook promises to somehow audit apps with access to “large amounts of information.”

The controversy popped off last weekend when The New York Times and Britain-based The Observer reported that Trump-affiliated Cambridge Analytica collected data from over 50 million Facebook accounts to manipulate voters’ opinions.

Things got worse when the U.K.’s Channel 4 got Analytica’s CEO on tape bragging about manipulating governments and denigrating U.S. officials.

Facebook has faced ongoing backlash behind the incident. Their stock has dropped 7.1 percent since Friday. The U.S. Federal Trade Commission has launched a probe, and the attorneys general of New York and Masschusetts want to begin their own investigation. There have also been calls for Zuckerberg to testify in front of Congress, but the CEO has ignored all of them, for now.