If a statement is false, that's the worst thing you can say about it. You don't need to say it's heretical. And if it isn't false, it shouldn't be suppressed.
Despite agreeing with the rest of the essay (which is very good), this is not true. Tiresomely standard counter-example: "Heil Hitler! No, there are no Jews in my attic."
Another monthly installment of the rationality quotes thread. The usual rules apply: