Agent provocateur

An agent provocateur (French for "inciting agent") is a person who commits, or who acts to entice another person to commit an illegal or rash act or falsely implicate them in partaking in an illegal act. An agent provocateur may be acting out of their own sense of duty or may be employed by the police or other entity to discredit or harm another group (e.g., a peaceful protest or demonstration) by provoking them to commit a crime--thereby undermining the protest or demonstration as a whole.