Four Big Tech CEOs - Facebook's Mark Zuckerberg, Amazon's Jeff Bezos, Sundar Pichai of Google and Tim Cook of Apple have appeared before Washington lawmakers to defend their firms against claims that they abuse their power to quash competitors. Facebook, Amazon, Apple and Google executives faced criticism over online dominance. The appearance comes as lawmakers consider tougher regulation and competition probes are under way. Some critics want the firms broken up. Big Tech CEOs, much of what they said, was predictable: We're not that big; competition is fierce; consumers love us.