Damn that's a biggie!
PENAL CODE SECTION 518-527
518. Extortion is the obtaining of property from another, with his
consent, or the obtaining of an official act of a public officer,
induced by a wrongful use of force or fear, or under color of
official right.
519. Fear, such as will constitute extortion, may be induced by a
threat, either:
1. To do an unlawful injury to the person or property of the
individual threatened or of a third person; or,
2. To accuse the individual threatened, or any relative of his, or
member of his family, of any crime; or,
3. To expose, or to impute to him or them any deformity, disgrace
or crime; or,
4. To expose any secret affecting him or them.
520. Every person who extorts any money or other property from
another, under circumstances not amounting to robbery or carjacking,
by means of force, or any threat, such as is mentioned in Section
519, shall be punished by imprisonment in the state prison for two,
three or four years.
snip>
523. Every person who, with intent to extort any money or other
property from another, sends or delivers to any person any letter or
other writing, whether subscribed or not, expressing or implying, or
adapted to imply, any threat such as is specified in Section 519, is
punishable in the same manner as if such money or property were
actually obtained by means of such threat.
http://caselaw.lp.findlaw.com/cacodes/pen/518-527.htmlEDIT...MAIL FRAUD - 18 U.S.C. 1341, makes it a Federal crime or offense for anyone to use the United States mails in carrying out a scheme to defraud.
A person can be found guilty of that offense only if all of the following facts are proved: First: That the person knowingly and willfully devised a scheme to defraud, or for obtaining money or property by means of false pretenses, representations or promises; and Second: That the person used the United States Postal Service by mailing, or by causing to be mailed, some matter or thing for the purpose of executing the scheme to defraud.
http://www.lectlaw.com/def2/m001.htm