Reply #133: the concept of public figure is fairly broad

[onenote]

The concept of the "public figure" is broader than celebrities and politicians. A person can become an "involuntary public figure" as the result of publicity, even though that person did not want or invite the public attention. For example, people accused of high profile crimes may be unable to pursue actions for defamation even after their innocence is established, on the basis that the notoriety associated with the case and the accusations against them turned them into involuntary public figures.

A person can also become a "limited public figure" by engaging in actions which generate publicity within a narrow area of interest. For example, a woman named Terry Rakolta was offended by the Fox Television show, Married With Children, and wrote letters to the show's advertisers to try to get them to stop their support for the show. As a result of her actions, Ms. Rakolta became the target of jokes in a wide variety of settings. As these jokes remained within the confines of her public conduct, typically making fun of her as being prudish or censorious, they were protected by Ms. Rakolta's status as a "limited public figure".

http://www.expertlaw.com/library/personal_injury/defamation.html#3