Kiener Plaza has a maximum capacity of 3,000 according to it's website (h/t Fired Up! Missouri for pointing this out earlier). As you can see from this picture, today's tea party did not even come close to filling it:
(screen shot from Gateway Pundit's page)
But of course, that won't stop Gateway Pundit from claiming that they had 4,000 people.
Since they claimed to have 10,000 people at their April rally, at least we can all agree that today was a giant #FAIL.