It's good to take a breath during this year's Great Clown Panic to see the history of such madness. Jesse Walker takes us on just such a tour, marked by his sense of humor and eye for historical detail.
The earliest he cites is from the early 80s:
In the spring of 1981, according to Benjamin Radford's recent bookBad Clowns, "police in Brookline, Massachusetts, issued an all-points bulletin asking officers to watch for a vehicle containing potential child abductors. The vehicle was distinctive: an older-model van with a broken headlight, no hubcaps, and ladders on the side. It was also full of clowns. Several children reported that clowns had tried to lure them into the dark van with promises of candy, and the sinister white-faced vagabonds were later reported lurking near Brookline's Lawrence Elementary School."
And: "None of these reports, in any of these cities, were ever substantiated. Always a Boogieman, never a John Wayne Gacy."
And this fine observation:
For one thing, pretty much everyone involved is clearly having fun. It's easy to focus on the fear-filled side of a scare—that's why we call 'em scares!—but surely one thing driving these little rumor-manias is the sheer pleasure of spreading a spooky story.
There's also this fine clip of a sneaky clown (check starting :55 or so):