The Brady Bunch and the rest of the Anti-2nd Amendment crowd tell us guns are bad. This indoctrination may have been caused by their parents, the media, an idol, literature, a bad experience, or whatever else. This belief can be a misunderstanding, a feeling, a curiosity, or a fear.
There is a term for fear of guns: Hoplophobia. Depending on your source, this word can be traced back to either 1962 or 1980, but in either case, it was created by legendary Gun Guru Jeff Cooper. He created the term to describe a "mental disturbance characterized by irrational aversion to weapons." Hoplophobia is described as an uncommon phobia in Contemporary Diagnosis And Management of Anxiety Disorders.
The term is derived from the Greek `Hoplites' which meant armored man. These were the spear guys who were part of the formidable phalanx formation of men they used to subjugate most of the known world.
The term has also been misapplied to all anti-gun people, which just isn't proper. It's a clinical term, not a general term. Basically, it's like calling a magazine a "clip" which is generally accepted, but not correct.
http://en.wikipedia.org/wiki/Hoplophobia
http://www.gunlaws.com/GunHate.htm
