I would say the Koch brothers have a darn good case of libel.
Of course they would have to employ several large law firms to sue all the people that have libeled them.
Liberal billionaires are threats to our way of life, and they are heros to these bums, and the only rich folks that tell the truth get all this garbage.
It's a received truth that the super rich are all Republicans who want to bring about anarcho-capitalism. The real truth is very much the opposite. The super rich, if anything, trend Democrat.
I have a theory that this is because once you've reached a certain level of financial wealth, what more satisfaction can you derive from earning more money? Instead they seek new avenues of "wealth", basically in the form of manipulating policy, culture, and what commoners are permitted to think. They like to call this "philanthropy".
The busybody streak is very strong indeed in liberals, and the rich ones are many times worse.