Definition - What does Vigilantism mean?
Vigilantism is a situation where people take on the role of the police without being authorized to do so and follow through with meting out justice. Lynch mobs are a common reference used to describe vigilantism. All forms of vigilantism are illegal in the US. The law allows for common people to hold someone by restraint that they believe has committed a crime, but they must then call the law to take the person from their restraint to the jail and court for proving any case.
Justipedia explains Vigilantism
Hate crimes are another common form of vigilantism. The idea has been present in the U.S. since inception; other areas of the world allow vigilantism in certain forms but for the most part, the act becomes illegal when any attempt to give a punishment for an offense is carried out.