Do that to the wrong pilot on the right day, and that is a hand that may find itself broken. I tell all of our pilots, short of an emergency, or backing the power levers on, do not touch any other pilot in the cockpit. I know how silly that must sound to have to say that, but years ago, we had a pilot who was upset with the co-pilot, and he poked him in the chest. The co-pilot stopped the conversation they were having and told the Captain not to touch him. Captain poked him again in the chest, F/O said I told you 2 times now not to touch me.....There will not be a third. Captain just had to push it. Some people just arent satisfied until someone has a foot in their a$$. F/O mopped the floor with his rear a$$. I was a line Captain at the time and witnessed the whole event. When the whole story got to the D.O., he fired the Captain and suspended the F/O for 14 days. This was years ago before anger management and counseling.