European lawmakers questioned Mark Zuckerberg in Brussels today for almost an hour and a half, asking him to address concerns about the Cambridge Analytica data leak and Facebook's potential monopoly. German MEP Manfred Weber asked whether the Facebook CEO could name a single European alternative to his "empire," which includes apps like WhatsApp and Instagram in addition to Facebook. "I think it's time to discuss breaking up Facebook's monopoly, because it's already too much power in only one hand," said Weber. "So I ask you simple, and that is my final question: can you convince me not to do so?" Belgian MEP Guy Verhofstadt then chimed in and asked whether Facebook would cooperate with European antitrust authorities to determine whether the company was indeed a monopoly, and if it was, whether Facebook would accept splitting off WhatsApp or Messenger to remedy the problem. The Verge reports: The panel's format let Zuckerberg selectively reply to questions at the end of the session, and he didn't address Verhofstadt's points. Instead, he broadly outlined how Facebook views "competition" in various spaces. "We exist in a very competitive space where people use a lot of different tools for communication," said Zuckerberg. "From where I sit, it feels like there are new competitors coming up every day" in the messaging and social networking space. He also said that Facebook didn't hold an advertising monopoly because it only controlled 6 percent of the global advertising market. (It's worth noting: this is still a huge number.) And he argued that Facebook promoted competition by making it easier for small businesses to reach larger audiences -- which is basically unrelated to the question of whether Facebook itself is a monopoly.