The Vigilante Panic is an ability for the Vigilante that allows him to kill during the day as a final resort right before his death, under the correct conditions.
When the Vigilante has been voted to be executed, the Vigilante can pull out an armed weapon, assuming he has any shots left. When unveiled, the Vigilante gets 30 seconds to speak, bypassing all blackmail set on him. Once his 30 seconds are up, the Vigilante will shoot his target. However, if the Vigilante has no target, he will instead, kill himself in the middle of court. If the Vigilante has shot and killed someone, he will be gunned down by marines or sniped by a sniper.
The point of Vigilante Panic is to ensure that a revealed Vigilante can make one final impact against the Mafia and the evil terrorizing the town. By nature, the Vigilante will die almost immediately after revealing himself, usually at night. This buff gives the Vigilante a final stand against the Mafia before dying or getting executed, possibly by the manipulation and lies of the Mafia or by asking to be voted guilty.
Of course, this would have to be an option and by default, should be off.