Earlier quoted context omitted.
Have you perhaps considered that recording people unobtrusively without their consent may be unethical or, at the minimum, rude?
It kind of ticks me off that people lose their collective "sh##" when things like Google Glass and Narrative help to give power to the civilian to record things in an unobtrusive manner but that people are totally fine with the ubiquitous billions of eye-in-the-sky surveillance cameras (see London) that the government uses to watch us every second.
The overlap between the “people” who don’t like Google to record their lives and the “people” who don’t care if the police do it is quite small...
But in any case the police in a democracy are at least nominally accountable to the populace, and can be checked via elections and other mechanisms. The mission of police is ostensibly for public benefit and includes criminal investigation, which surveillance could arguably help with. Google is a multinational corporation accountable primarily to itself which wants the data to help with its advertising business.