"Filthy" seems like small potatoes next to painting us as Nazi sympathizers, lunatics, or child molesters, all of which seem to be in vogue here, and completely permissable under "the rules of the FR religion forum".
As far as I've been able to determine, you can call groups of people anything you want as long, as you don't specify individual FReepers.
I haven't seen anyone here called a "lunatic" nor a "child molester." Please provide some substantiation for that outlandish claim.
And it was Pius XII who was a "Nazi-sympathizer" and he's long dead. As for your current bishop of Rome, Ratzinger was a Hitler Youth. The jury's still out.
Your complaint seems like more defensive, Roman Catholic hyperbole.