See Civil Rights Act of 1964. Many of the act's opponents were dyed-in-the-wool racists and bigots, and the rest of us can be glad that they lost. But there were some others who opposed the act because they understood that a slippery slope was being created.

Those are the limits most people are familiar with. They're reasonable and expected but even in the US businesses have 'the right to refuse service to anyone.' They work in the same way that you can fire someone, but you can't fire someone for being black, or a woman.

The OP claimed that that did not exist at all in Germany.

It certainly is illegal in France. Refusing to sell without a valid reason is an exception to contract liberty since the sixties (article L. 122-1 du code de la consommation). The former situation was seen as biased in favor of the sellers.

Whether alleged violation of the user term is a valid reason is open to questions. Without going to court, I strongly doubt it is.

Facebook being a human right would be very interesting to read about. I wonder if one could appeal account terminations to ICANN.