It is censorship. Whether you'd consider it acceptable or not is a different matter, but don't try to duck the important decision you'd have to make about it. Many groups throughout history have thought that silencing people they didn't like was a matter of hygiene—including the Nazis, as a matter of fact. It's an enticing concept, using different standards when it comes to people you hate.
Advocating throwing human beings into ovens isn't acceptable. If you find yourself on the other end of that opinion, do some deep, deep soul searching. It's not about speech at that point.
