Extortion (also called blackmail, shakedown, outwresting, and exaction) is a criminal offence which occurs when a person unlawfully obtains either money, property or services from a person(s), entity, or institution, through coercion. Refraining from doing harm is sometimes euphemistically called protection. Extortion is commonly practiced by organized crime groups. The actual obtainment of money or property is not required to commit the offense. Making a threat of violence which refers to a requirement of a payment of money or property to halt future violence is sufficient to commit the offense. Exaction refers not only to extortion or the unlawful demanding and obtaining of something through force, but additionally, in its formal definition, means the infliction of something such as pain and suffering or making somebody endure something unpleasant.

Extortion is distinguished from robbery. In armed robbery, the offender takes goods from the victim with use of immediate force. In robbery goods are taken or an attempt is made to take the goods against the will of another—with or without force. A bank robbery or extortion of a bank can be committed by a letter handed by the criminal to the teller. In extortion, the victim is threatened to hand over goods, or else damage to their reputation or other harm or violence against them may occur. Under federal law extortion can be committed with or without the use of force and with or without the use of a weapon. A key difference is that extortion always involves a written or verbal threat whereas robbery can occur without any verbal or written threat.

In the English language, black sheep is an idiom used to describe an odd or disreputable member of a group, especially within a family. The term has typically been given negative implications, implying waywardness. It derived from the atypical and unwanted presence of other black individuals in flocks of white sheep.

In psychology, the black sheep effect refers to the tendency of group members to judge likeable ingroup members more positively and deviant ingroup member more negatively than comparable outgroup members.

The term originated from the occasional black sheep which are born into a flock of white sheep due to a genetic process of recessive traits. Black wool was considered commercially undesirable because it could not be dyed. In 18th and 19th century England, the black color of the sheep was seen as the mark of the devil. In modern usage, the expression has lost some of its negative connotations, though the term is usually given to the member of a group who has certain characteristics or lack thereof deemed undesirable by that group.

David Michael Letterman (born April 12, 1947) is an American television host and comedian. He hosts the late night television talk show, Late Show with David Letterman, broadcast on CBS. Letterman has been a fixture on late night television since the 1982 debut of Late Night with David Letterman on NBC. Letterman recently surpassed friend and mentor Johnny Carson for having the longest late-night hosting career in the United States of America.

Letterman is also a television and film producer. His company Worldwide Pants produces his show as well as its network follow-up The Late Late Show with Craig Ferguson. Worldwide Pants has also produced several prime-time comedies, the most successful of which was Everybody Loves Raymond, currently in syndication.

In 1996, David Letterman was ranked #45 on TV Guide's 50 Greatest TV Stars of All Time.

Letterman was born in Indianapolis, Indiana. His father, Harry Joseph Letterman (April 1915 – February 1973), was a florist of British descent; his mother Dorothy Letterman (née Hofert, now Dorothy Mengering), a Presbyterian church secretary of German descent, is an occasional figure on the show, usually at holidays and birthdays.