As a huge baseball fan, I think the dumbest thing you could do, is run out onto the field of play. Great, you got your 5-10 seconds of fame. The guy who ran out onto the field at an Atlanta Braves game is going to have plenty of eyes on him, but to his surprise, it's going to be the security guard in this video that will get the fame. The security guard made a picture-perfect football tackle. He had his head on the side, wrapped him up and used his feet to drive him into the ground (in this case the backstop). Check out the video below.
Here's the tackle from another angle.