Why is his behavior illegal? What law is he breaking? Public nuisance, maybe?
Your reaction depicts the typical attitude to surveillance. What this guy is trying to point out is that we are already under surveillance and we have no control over it and no idea who is doing it or how thoroughly they are doing it.
(a) camera technology won't improve over time
(b) no entity has an EagleEye-like ability to summon surveillance footage from various cameras
(c) employees, contractors and subcontractors of such entities won't abuse their access to sensitive information
is quite weak.
"operated by more reputable entities than some random creep", you know you're talking about companies in a capitalist society, right? Not exactly famous for being particularly reputable to say the least.
There are technologies like ShotSpotter - http://www.shotspotter.com/ - which according to the NYT has enough fidelity to pick up things like "doors slamming, birds chirping, cars on the highway, horns honking." as well as conversations:
http://www.nytimes.com/2012/05/29/us/shots-heard-pinpointed-...
Also, think about surveillance drones - they are coming: http://rt.com/usa/news/dhs-drone-surveillance-napolitano-156...