Mark Zuckerberg testified in the U.S. Senate Tuesday. Image: C-SPAN.Facebook founder Mark Zuckerberg told U.S. senators his social media platform didn’t do enough to protect users’ privacy or prevent foreign interference in elections. He says he accepts responsibility, and even welcomes the possibility of new federal regulation. But when it was Sen. Dan Sullivan’s turn to ask a question, Zuckerberg wasn’t all that compliant.Listen nowSullivan opened with a question aiming to honor the success of Facebook.“Quite a story, right? Dorm room to the global behemoth that you guys are,” Sullivan said. “Only in America. Would you agree with that?”No. Zuckerberg did not agree.“Well senator, there are some very strong Chinese internet companies,” Zuckerberg said.“Right but …,” Sullivan paused and offered some stage direction. “You’re supposed to answer yes to this question. Ok? C’mon. I’m trying to help you, right? Gimme a break. You’re in front of a bunch of senators. The answer is yes, so thank you.”It was a light moment in a long hearing. But Sullivan went on to make a point about the dangers of regulation. Zuckerberg made clear he and the Alaska senator don’t see it the same.“I’m not the type of person that thinks all regulation is bad,” the CEO said. “So I think that the internet is becoming increasingly important in people’s lives. And I think we need to have a full conversation about what is the right regulation, not whether it should be or shouldn’t be.”Zuckerberg may sound altruistic there, like he just wants what’s best for society. But Sullivan questioned whether Facebook would use its political power to push for regulations that cement its lead on competitors.“One of my biggest concerns about what you guys are doing is that the next Facebook – which we all want, the guy in the dorm room, we all want that, to start it – that you are becoming so dominant that we’re not able to have that next Facebook,” Sulllivan said.Zuckerberg said shutting out the little guy wouldn’t be his approach to regulation, though he said the concern is valid.Sullivan only had a few minutes, but his name also came up when Democratic Sen. Chris Coons asked Zuckerberg about malicious or phony Facebook pages. Just that morning, the Delaware senator said, he found out someone had made a fake Facebook page for him. Coons said he went online and found it.“And there’s my picture with Sen. Dan Sullivan’s family. Same schools I went to. But a whole lot of Russian friends,” Coons said. “Dan Sullivan’s got a very attractive family, by the way.”No one disagreed.