A tremendous amount of taxpayer resources were wasted on this hoax. The penalty needs to be stiff and needs to include at least some jail time as a deterrent to other whack jobs looking for their 15 minutes. You cannot create a climate where hoaxing the cops is tolerated and excused.
Couple of guys down Wall Street way who wasted as much as these people - like a hundred million times as much - where are the news reports and calls for public hangings?
True justice requires some attention to scale and intent...