RE: Keeping Non Members off the field
I don't think anyone was suggesting murder. However the law in Texas and PA (at least) allow the use of lethal force under certain circumstances. You don't have to use it. Just like you can drive a car or choose to walk. Some folks would even rather be murdered than defend themselves (the Amish for example). Just like police can shoot people under certain circumstances however they (usually) try all other solutions first.