For obvious reasons, many jurisdictions make it a crime to disguise yourself as another person and do things that damage that person. What Carlson did is not simply a prank. It may be due to childish or stupid thinking, but that is not relevant to the determination of whether it is a crime.
Certainly Olbermann has a civil case, which I hope he will pursue, as he can afford it. But depending on the states involved, there may be a criminal case as well.
This is dirty politics involving crude, undeniable deceptions. It's the kind of thing done by the Nixon campaign in 1972 (by the likes of young Karl Rove), or to far more violent effect by the FBI COINTELPRO operation (as one example, they forged attack letters by leftist leaders to create deadly divisions within their political groups). More recently we have seen Breitbart et al. present crudely deceptive edited video in the ACORN, Sherrod Brown and other affairs.
What kind of political discourse can we look forward to if it becomes common practice to simply hoax the identities of your political opponents without providing any indication that this is not the work of another person or meant as satire or critique?
Right-wing politics in this country has degenerated into a total free-for-all of deception and dirty play. The rhetoric justifies any means, and most means short of violence are already being employed. (The handful of violent incidents so far are a harbinger of where the rhetoric is already pointing.)
I'm not sure this can be reversed, but the Carlson case, for being so crude and simple to understand, may provide an important opportunity to finally set any kind of example about what is allowable.
IMPERSONATION, entry from Law Encyclopedia:
http://www.answers.com/topic/impersonation The crime of pretending to be another individual in order to deceive others and gain some advantage.
The crime of false impersonation is defined by federal statutes and by state statutes that differ from jurisdiction to jurisdiction. In some states, pretending to be someone who does not actually exist can constitute false impersonation. For example, suppose Bill attempts to evade prosecution for a crime by giving the arresting officer a fictitious name and address. In Colorado, where " person who knowingly assumes a false or fictitious identity and, under that identity, does any other act intending unlawfully to gain a benefit for himself is guilty of criminal impersonation," Bill could be charged with a crime (Colo. Rev. Stat. Ann. § 18-5-113(1) ). In this situation, the benefit Bill hopes to realize is avoiding prosecution, so that element of the offense has been satisfied. To be charged, the defendant does not need to seek a monetary benefit from the impersonation.
In New York, giving only a fictitious name does not constitute false impersonation. Under New York law, criminal impersonation is committed when an individual "mpersonates another and does an act in such assumed character with intent to obtain a benefit or to injure or defraud another" (N.Y. Penal Law § 190.25 ). In other words, it is illegal to impersonate a real person, but not a fictitious one. Thus, if Carol forges Ann's name on checks made out to Ann so that Carol can cash the checks, Carol could be guilty of false impersonation — but only if Ann is a real person. Such laws are designed to protect innocent people from the losses they may incur owing to the wrongful acts of others and to restore any loss of dignity and reputation they may have suffered as a result of impersonation.
Most state laws also provide that the impersonation of a public official is a criminal act. In Texas, impersonating "a public servant with intent to induce another to submit to his pretended official authority or to rely on his pretended official acts" is a crime (Tex. Penal Code Ann. § 37.11 ). Depending on the jurisdiction, the public servant being impersonated does not always have to actually exist. For example, suppose Carl pulls over a driver, shows her a fake police badge, and reprimands her for speeding but tells her that he will not arrest her if she pays him $50. Carl's actions constitute the crime of false impersonation, in addition to any other crimes, including extortion, that may apply to the situation. Thousands of criminal reports are filed every year by individuals victimized in various ways by persons impersonating police officers.
Under federal law, pretending to be "an officer or employee acting under the authority of the United States" in order to demand or obtain "any money, paper, document, or thing of value" can result in a fine as well as imprisonment for up to three years (18 U.S.C.A. § 912). Like state false impersonation statutes, the federal law also seeks to protect interests such as the dignity and prestige of individuals, especially those who hold federal office. Federal statutes also prohibit other types of impersonation, including pretending to be a U.S. citizen; pretending to be a U.S. officer or employee attempting to arrest or search a person or search a building; pretending to be a creditor of the United States or a foreign official; and pretending to be an agent or member of 4-H or of the Red Cross.