An agent provocateur (French for 'inciting agent') is a person who actively entices another person to commit a crime that would not otherwise have been committed and then reports the person to the authorities. They may target individuals or groups.[1]
In jurisdictions in which conspiracy is a serious crime in itself, it can be sufficient for the agent provocateur to entrap the target into discussing and planning an illegal act. It is not necessary for the illegal act to be carried out or even prepared.
Prevention of infiltration by agents provocateurs is part of the duty of demonstration marshals, also called stewards, deployed by organizers of large or controversial assemblies.[2][3][4]