Legal uses of secret identity include people placed under witness protection programs to protect witnesses in criminal trials from retaliation from the criminal organizations they inform against. Law enforcement and intelligence agents often use secret identities in undercover operations in order to infiltrate criminal or foreign organizations for the purposes of investigations. Entertainers like professional wrestlers sometimes hide their identities beyond simple stage names in order create an appealing mystique for the audience.
Writers also often use pseudonyms in order to hide their identity. In some cases, such as with James Tiptree, Jr the writer will use a pseudonym because the image required by the genre does not match the writers actual identity. In the case of Richard Bachman, Stephen King wanted to know whether as his writing "unknown" writer would get as much interest as his non-pseudonym work. Finally, a writer who writes in different genres may use different identities for each genre.
In politics, the assumption of a secret identity is sometimes used to avoid adverse political consequences of an identity being publicized. Famous secret identities in politics include Deep Throat, the unnamed source for Watergate information and X, who wrote a famous essay outlining the United States policy of containment and who was later revealed to be George Marshall.
On the Internet, an alias or nickname is often used for privacy and abbreviation. (See also Internet friendship and Sherry Turkle's academic work.)
Secret identities of real people include:
In fiction, secret identities are typical elements of superheroes who hide their identities both to preserve a private life and protect their loved ones from retaliation from criminals. The artistic purpose of the concept on the part of the writers is that it allows the characters to have ordinary lives which can allow for human drama as well as create tension with the effort needed to preserve the secret.
Famous fictional characters with secret identities include: