The existence of argumentation presupposes the existence of scarcity; argumentation arises as an a priori peaceful means to resolve conflict over a scarce good (two or more people cannot use the same means towards different ends at the same time). Thus, anyone trying to confiscate their property without consent is in a performative contradiction, as you cannot reconcile peaceful argumentation with the act of aggression. This extends to the individual's body, as argumentation ethics presupposes self ownership: argumentation is a form of action, which can only occur through the control of a man's body.

Applying this to speech, you are not engaging in a form of aggression when you are stating words. Thus, you have no right to prosecute the individual.