If you're still on the fence about how the NFL lowered the boom on the New Orleans Saints for systematically targeting opposing players for injury, may I direct you to this story.
See defensive coordinator Gregg Williams urge players to target opposing team members who have had concussions or other injuries. For example, here he is whipping up his players before the San Francisco 49ers game last January:
"We need to decide on how many times we can beat Frank Gore's head. We've got to do everything we can in the world to make sure we kill Frank Gore's head. We want him running sideways. We want his head sideways."
That's way, way over the line.