Most data by itself is useless, even things we consider "private" like SSNs, credit cards, etc. They're like $20 for a bundle on the black market. But if you can link that stuff to browsing, location, or transaction history? Anyone with that can read you like a book. It's not about what data is collected so much as it is how much data is collected - and how much of the collection can be traced back to you through a cookie or IP address. That's the big problem. Anyone with enough random data about you can put together your life piece by piece.

In the context of mainstream news reports on big tech, the "data" they're referring to is personal, or at the very least able to cause behavioural changes on an individual level.

Journalists don't care about non-personal data ("only x% of users use the symbol insertion tool in Word 2016") - even though Microsoft certainly does - because it makes for a mundane news story.

But this shouldn't matter. We still have a subconscious and we sometimes do things that we don't really think through, or do them on auto-pilot. So you could be doing things which you don't think through and they are still indicative of who you are as a person. But now, you don't know this part of you and you end up in a situation where some algorithm running on some servers somewhere is a better predictor for what you want (among other things) than your own thoughts.

Truth is people seem to not care about their subconscious. And they fail to understand the power of data when combined with 1 million other people. I still hear the response 'Well I have nothing to hide' way too much from people living in 2021.

A fair point, though the data of interest to marketers, and others making use of targeted influencing and/or surveillance, is.