Ostracism

Ostracism (Greek: ὀστρακισμός, ostrakismos) was a procedure under the Athenian democracy in which any citizen could be expelled from the city-state of Athens for ten years. While some instances clearly expressed popular anger at the citizen, ostracism was often used preemptively. It was used as a way of neutralizing someone thought to be a threat to the state or potential tyrant.

• http://en.wikipedia.org/wiki/Ostracism