When a speaker relies on irrelevant information for his or her argument, thereby diverting the direction of the argument, he is guilty of the red herring fallacy (so named for a popular myth about a fish’s scent throwing hounds off track of a pursuit). If you say, for example, “I can’t believe that police officer gave me a ticket for going 70! Yesterday, I saw a crazy driver cut across three lanes of traffic without signaling while going at least 80. Why aren’t cops chasing down these dangerous drivers instead?” you would be using a red herring. There may well be worse drivers than you, but that doesn’t change the fact that you broke the law.