Supposedly this trend started in Bakersfield or near there where people would dress up like "killer clowns" and scare people around town. It has now spread to Britain and France.

http://news.yahoo.com/no-laughing-ma...005440754.html

One of these idiots is gonna get himself killed by messing with the wrong guy. And I won't be particularly upset about it.

Though it has definitely spread to Arizona. A number of clowns have been spotted asking for votes recently around Phoenix and Tucson.