This absurd thread is a game of telephone as well.
The claim was "We're prohibitively expensive to poll", and I am correct it is cheaper to poll humans. i.e. query X regarding Y, where X is {humans with eyes|cars with cameras}, and Y is the evaluated state of some location at some time.
I do agree if the poster had written "it's cheaper to set up a network of self-driving cars than spies"...well when I put it that way :P...but jk sure I'll say spies.