Pie throwing

Cream filled or topped pies are favorite props for humor, particularly when aimed at the pompous. Throwing a pie in a person's face has been a staple of film comedy since Ben Turpin received one in Mr. Flip in 1909, and is often associated with clowns in popular culture. Pranksters have taken to targeting politicians and celebrities with their pies, an act called pieing. Activists sometimes engage in the pieing of political and social targets as well. One such group is the Biotic Baking Brigade. "Pieing" can result in injury to the target and assault or more serious charges against the pie throwers.

-Pie throwing as defined by Wikipedia