About 500 people should join you. It is an abomination.
Don't worry. I seriously doubt this will last long, if and when it actually gets put up. If it was me, I would leave it up a bit, then do several sessions of different sorts of graffiti (to make sure that it makes all the major news outlets), and then take it out in a spectacular manner that is sure to make headlines.
And then rinse and repeat as necessary... Have faith in the people of Oklahoma to clean up their own mistakes.
But, I really didn't mean that for real... Just speaking hypothetically here... of course... I would never think of doing something like that...!