you've just cut off a biker
on the road... you didn't really care anyway... then in a flash the bike whips past and your car mirror or window has been smashed by his ball pein hammer.
the ball pein is preffered because all the force of the blow is concentrated on a very small point it will break glass, saftey glass, and human skulls very easlily.
-i was chatting on my cell phone, drinking a latte and i cut off this biker
and he smashed my window out with a hammer!
-oh... you got ball peined?