IMO a company that would rely on this kind of invasive surveillance is not really interested in the well being of their employees. There are far better and less invasive ways to evaluate employee satisfaction and fulfillment than hiring an outside organization to "dig up dirt", for the lack of a better term.

To me it's no different than a company hiring a PI to follow me around so they can report back how many drinks I have on the weekend at a barbecue. Or following me around to find out if I bought a new suit and tie (oh no, might indicate I'm going for an interview!). Just because it's being done digitally doesn't make it any less invasive.

What's next? Grocery stores start selling my buying habits to my employer? That would definitely give them more insight into whether I'm happy and committed. Banks/Credit card companies selling my purchase history?