With enough data you can segment for almost any group.
- Who is likely to vote Bernie?
- Who is gay?
- Who is gay, but not out?
- Who is cheating on their wife?
Etc etc..
If you can't see the potential for harm at both the individual level (think extortion) or political level of that kind of power I'm not sure what would convince you.
At some point in the reasoning chain you reach the bad thing that is bad because its intrinsically bad and if you try to reason more you'll just go in circles. Or you enter a philosophical debate of such depth that it's stupid to have it with internet strangers.
- Who is likely to vote Bernie?
- Who is gay?
- Who is gay, but not out?
- Who is cheating on their wife?
Etc etc..
If you can't see the potential for harm at both the individual level (think extortion) or political level of that kind of power I'm not sure what would convince you.