purpose isn't really for businesses, but rather businesses are a conduit to get us comfortable with this technology. These sort of cameras will soon be used for 'security purposes'. Imagine walking into a store and the store camera being able to scan your face and pull up a profile on you in some centralized database. Don't forget your cellphone serves as a walking GPS tracker. There's also a reason cell phones come with cameras on both sides now. Just about every single move you make and everything you do is being recorded. Let's not forget more and more cars being outfitted with onstar and other 'smart' technologies where someone can remotely enable or disable your car. You might think it's helpful when the company can unlock your car after a call, but you won't think it so innocent knowing they can also lock you into your car if necessary. This gives TREMENDOUS amounts of power to governments and corporate entities. They pretty much have the ability to access your thoughts and actions on a whim, and if they don't like what you're thinking, you can easily be labeled a dissident and punished in some form or the other. There has actually been discussions of prosecuting people for THOUGHT CRIME. Oh, you're thinking in a manner that is considered 'threatening'? We've got problems buddy.
This pretty much coincides with the 'all seeing eye' that you will notice on the back of your dollar bill. That fits that concept perfectly. Ultimately, you are but a node on the 'smart grid'.