Well one must confess to having experienced the compulsion to smack a student in the face for arriving late and ill-equipped for a lesson but seldom whilst airbourne! But their legs? Now that's another issue all together - how many clam up on the rudder pedals making it practically impossible for instructor input if neccesary?! Other than placing my hand on their knee in a quasi-molesting feel-up kinda action (to distract attention!) there's not much else left in the bag for that one is there?!
VFE.