Zuckerberg: Congressman, I’m not, I’m not familiar with that.
Zuckerberg: I do not know off the top of my head.
Zuckerberg: Congressman, I do not know off the top of my head but I can have our team get back to you afterward.
This guy must have a whole team of people coaching him on what he can overtly lie about, what he can obfuscate - and when he can't do either, how to change the subject.