The main assumptions you need to be wary of data harvesting are: 1. (Some) people will act against your best interest for their own gain (most often to get mon

The main assumptions you need to be wary of data harvesting are: 1. (Some) people will act against your best interest for their own gain (most often to get money, but, sometimes, to undermine people or ideas they do not like) 2. There are always things that you believe/stand for (pro-abortion, pro-BLM, anti-vaccine, anti-pesticide, pro-house garden, etc.) that someone somewhere disagrees with. These are increasingly identifiable and actionable on. 3. There are always traits (skin color, medical disposition, height, IQ, etc.) that are identifiable and therefore actionable on. 4. Modern data collection is much less visible and obvious than it's ever been. This means the people doing this collection and the people acting on this data are subject to less societal and legal pushback than before, and receive this pushback much later along the line (meaning they can build more momentum behind whatever they're doing before getting called out, if they ever are) 5. Data is never secure indefinitely. Eventually, there's a good chance it's sold to the highest bidder, regardless of who that bidder is or what their intentions are. With the above assumptions, we can see people are more empowered to discriminate against and take advantage of others. They are also more easily able to remove civil liberties without getting called out. I think some people believe that the people who would do this kind of thing are few and far between, but it only takes one person with weird ideas and some clout getting this kind of capability to make life miserable for a group of people. And people probably underestimate the number of people with low empathy in the population. Here is an extreme but real world example of what can happen: https://en.wikipedia.org/wiki/Dehomag https://en.wikipedia.org/wiki/Dehomag