Mark Zuckerberg appeared before Congress Tuesday, and for five hours, senators who appeared to have halting grasp of the company\u2019s intricacies questioned the Facebook CEO on topics ranging from Russia to artificial intelligence. Zuckerberg for the most part gave considered answers to their questions\u2014except when it came to the specifics of how users can control their privacy. That Zuckerberg would dodge uncomfortable questions is a disappointment, though maybe no surprise.