That's a pretty complicated explanation, given that (1) every major city PD already makes ample use of street-level CCTV footage, and (2) it involves local-fede

That's a pretty complicated explanation, given that (1) every major city PD already makes ample use of street-level CCTV footage, and (2) it involves local-federal cooperation (the FBI is seemingly the ones flying these planes). If we're speculating baselessly, my guess would be that, like all cops, the FBI has a bloated surveillance budget and loves trinkets. Why waste shoe leather or sit in a car for hours when you can justify a joy ride in a plane while you watch the bad guys?