According to a slew of recent articles, the frenzy started by a modest cartoonist was unintentional.
Molly Norris drew a cartoon (you can see it here) in which she depicted Mohammed as a spool of thread, a cherry, a box of pasta, and a domino, among other things, under the banner “Everybody Draw Mohammed Day.” The cartoon was drawn as a poster, and so thousands of people have taken up the cause believing that May 20th would be Everybody Draw Mohammed Day. The catch is that Norris only intended the cartoon as a one-off, a response to the ridiculous restrictions of free speech and cowtowing to religious fanatics by Comedy Central for censoring the recent South Park episode in which Mohammed was depicted in a bear suit (it turned out not to be Mohammed, however, but Santa).
Nonetheless, people glommed on to the idea of Everybody Draw Mohammed Day, resulting in Norris having to publish this statement on her web site.
Although Norris did not intend Everybody Draw Mohammed Day to be a real day, I don’t think the momentum can be stopped at this point. Norris has made it clear that she is not the point person for this project, so don’t send drawings to her. There is, however, a Facebook page (see the aforementioned article), so that may act as a conduit.
But I don’t think there needs to be a central organizing force. This thing has already gone viral and if everyone decides that May 20th is Everybody Draw Mohammed Day, then all it will take is for everyone to follow through and actually draw Mohammed, and post the results publicly (although I suspect anonymously—terror is still terror, and it’s still a winning strategy).