There is no difference between "filter out black people" and "filter out X, (X correlates 99% with black people)". And I mean that legally, morally and practically.

Here's a list of ways around "cannot filter by race". It took 2 seconds on google: https://www.searchenginewatch.com/2011/12/06/how-to-target-e...

But, you seem to be shifting the goalposts pretty significantly. So, do you agree with the base point that targeted ads can produce pretty bad results?