Agreed. One also should not expect there to be no consequences.
HR person: "Mr. Carter, we have done a social posting history on the candidate you interviewed last week and recommended for hire at a starting salary of $105,000 per year. It seems she has quite a few posts regarding the gassing of Jews and some rather cruel things she wants to do to homeschooling parents. Seems she hates Christians as well."
Mr. Carter: "Again? That's the third one this year. Are all Harvard graduates like that? Send her a polite rejection letter."
HR person: "Roger that, sir!"
I guess if you are willing to express some stupid opinion,you should be just as willing to accept the consequences of what your potential employer might think about it.