Are they though? The odds of any kind of coordinated response that could seriously threaten the billionaires seem next-to-none. Flock seems to be a lot more offensive than defensive - it enables the targeting and mass surveillance in order to find and punish the 'right people', as well as mass tracking to create yet another datapoint to understand the way people move, think and coordinate. The defensive side is already covered through internet services, like social media. They don't have much to fear. I reckon that a powerful/rich enough person could kill a stranger on the street in plain view of a huge crowd and have absolutely nothing happen to them.