There's no expectation of privacy because you're in public. Also, the security cameras are visible and there are possibly signs informing you of this. I have yet to see a "your actions are being recorded for product improvement purposes" warning on a website. Or maybe I did, but I tuned it out because it got buried in the standard cookie warnings.
Can you link to some examples of some "well hidden" cameras at a major retailer? Most retailers don't bother to hide their cameras, so they're just kinda lying out there. They're not overtly obvious, but if you know where to look (eg. ceilings), you can find them.
>And isn't a website you don't own a public place?
Not really, it's public in the sense that anyone can access it, but it's also private in the sense that all your activities are instanced and not visible to anyone else.
>Do you expect Google not to track what you do on their site?
Facebook got flak a few years back when it was revealed that they were surreptitiously recording everything you typed when you were creating a post, even before you hit submit[1]. Clearly the average person doesn't expect that their activities to be recorded 24/7.
How do you feel about physical stores that use video cameras? That seems like the most equivalent thing in the real world to me.