Revenge is sweet. I just posted a birthday card to my brother and used a cheaper christmas card stamp on the envelope, thereby defrauding Australia Post of five cents. That'll learn 'em to not have non religious stamps available. I am five cents richer.
There are non religious stamps, but our Post Office did not have any.
Which reminds me of Fruit Cake (I think) who brought up, possibly in comments, that she would not bother to pick up five cents from the ground.