A posterboy (or “poster boy,” also “postergirl/poster girl” as appropriate) is a usually famous person who is heavily associated with and/or generally found to represent a given movement, subculture, religious group, fandom, etc. to people who do not belong to said group. The name comes from their frequent appearances in the group’s promotional materials, especially posters. Generally, they are very outspoken, opinionated and experienced within their group, though a single act gaining major media attention can also thrust someone into posterboy-dom. Examples of posterboys include Richard Dawkins for the atheist community and Dan Savage for the homosexual community.
Unfortunately, due to the vocal minority effect, and the fact that sensationalist actions and statements tend to gain the most mainstream media attention, many posterboys hold wildly extreme views that aren’t supported by the majority of their groups, leading many to unfairly judge others who are normally perfectly sane.
I hate calling myself an atheist
anymore because our posterboys like Dawkins and Hitchens make us all look like asshole