This is a defensive procedure that often does not work on it's own. Often performed when being choked in a movie. The victim forces their palm into their assailant's face, to try and remove them from their throat. If this happens to you within the first 15 minutes of a movie, you will die: end of story.
Two guys watching a horror movie:
Guy #1: Oh, that guy's dead.
Guy #2: How do you know?
Guy #1: We just started the movie, he's being choked, and he's resorting to the Fightpalm; I give him less than a minute left to live.