You can search on all sorts of keywords that will let you know someone is one of "them", and so not the kind you want in your rental property or whatever.
Now I personally believe that individuals ought to be able to rent to whomever they please, because discrimination in renting or other businesses is not a nation threatening situation. The same is not true for freedom of speech, which I regard as absolutely essential to balancing out the political system in America.
But even though I personally don't believe in forcing people to rent to people to whom they don't want to rent, I also believe in using the left's own tactics against them. I believe in forcing them to live up to their own book of rules.
So in that regard, I hope they eat Facebook for breakfast.
I disagree and think that enforcing anti-discrimination in renting has and well generally help more than it will hurt the rights of landlords. But regardless of that, I think we agree this is a good legal test for Facebook. They will have to open up their algorithms and prove that they are nondiscriminatory.