"Mr. Zuckerberg, would you be comfortable sharing with us the name of the hotel you stayed in last night?" Durbin, a Democrat from Illinois, asked.
Zuckerberg responded by nervously giggling and saying "Uhhhhh...no."
Durbin continued, asking, "If you've messaged anybody this week, would you share with us the names of the people you've messaged?"
Zuckerberg said no, he "would probably not choose to do that publicly here."
All this was to make a point about users' expectations for a right to privacy, Durbin said.
"I think that may be what this is all about," said Durbin. "Your right to privacy, and 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 said.
Durbin called it a "question basically of what information Facebook is collecting, who they are sending it to, and whether they ever asked me in advance my permission to do that."
"Is that a fair thing for a user of Facebook to expect?" Durbin asked.
Zuckerberg said he agrees and thinks "everyone should have control over how their information is used."