None of which makes either spy-camera's or Google Glass' recording facility any more acceptable.
Okay -- enough of the theoretical; down to the personal. I'm a commuter cyclist. A very, very law-abiding commuter cyclist (last group ride I went on, the only person quite as meticulous was a LAB instructor). I damn well have cameras, one in obvious view (making the recording I do not surreptitious), others less so (with a circular buffer being recorded over until/unless an impact is detected or manual trigger pressed), and if someone objects? Fuck you. My safety (and ability to demonstrate fault or chain-of-events in court) trumps the reasonable expectation you don't have of being unrecorded in public.
And if you want to throw a punch over being recorded? Better be sure you really did get every device.