<quote>there's no way they can find out (legally)</quote>
Really? Is that really true? What about all the forms one signs, allowing for background information check (education, employment information, etc)?
>Plenty of "serious" firms ask about last salary earned (in fact, if you were to fill out an application on line
Are you saying that a "serious" firm would have you fill out an application (online or otherwise)? I thought any career level job would expect a resume/CV.
Big finance firms (EG, top 3 in the world) require tax documentation and will rescind offers if your comp was exaggerated.