The collection Microsoft does is nothing like that, it's literally things like "did this users use the action center" or not. In Cortana it tracks your search, JUST like Google Now/Siri. It's not going through your documents or personal stuff at all. It's not even on the NSA level meta data, which I do have a problem with. It honestly sounds like you don't even know what it's tracking at all. Your analogy makes 0 sense at all. You might as well claim that "heat mapping" on websites is akin to rummaging through your trash.