I think HN and the public are extra sensitive to the concepts of "mass surveillance" by the government. A van parked out of a house doesn't seem like mass surveillance (even though it probably could be) but a plane "circling US cities" for some reason, raises these concerns to a higher level.

Also, the story is just ripe for the viral nature of the current news cycle: Mix in one part government entity (FBI), one part privacy (seeming mass surveillance) and one part secrecy (hidden corps) and you've got yourself a recipe for media success in 2015! In all seriousness, if the planes were "drones" you'd have a social media sharing grand slam.