That's not true. Most countries don't have an official concept of social classes, so that makes it okay to say that you earn above X (e.g. to someone lending you money) even though you're not making anything? It's still lying.
Edit: guys, you should probably consult a lawyer. If you don't refuse to disclose but lie instead, that's called deception and at least in the EU it's a criminal offense. Also, morality, huh?