Even Mark Zuckerberg has limits on what he’s willing to share.

In a rare light-hearted exchange during his public grilling before U.S. senators Tuesday, the Facebook CEO told Sen. Dick Durbin that no, he would rather not share personal details of his life with the U.S. Congress.

“Mr. Zuckerberg, would you be comfortable sharing with us the name of the hotel you stayed in last night?” asked Durbin, an Illinois Democrat.

“Um… no,” Zuckerberg said after pausing, then smiled as the room laughed.

“If you’ve messaged anybody this week, would you share with us the names of the people you’ve messaged?” Durbin continued.

“Senator, no, I would probably not choose to do that publicly here,” Zuckerberg replied.

“I think that maybe is what this is all about,” Durbin said. “Your right to privacy. The limits of your right to privacy and how much you give away in modern America in the name of quote, ‘Connecting people around the world.'”

Durbin was among many senators who grilled Zuckerberg on what the social network collected on its users, following revelations that the Donald Trump-affiliated data mining firm Cambridge Analytica scooped up data on millions of Americans without their knowledge.

(AP)