Just because there's notably wacky people doing this doesn't invalidate the suggestion. Part of a real problem with police is that they often have no idea what the limits are. If everyone had the same standard script, police would get away with much less, and the good ones would learn how far they and their colleagues can take a stop. Holding them to account is a civic responsibility. Record everything and know your rights, and never talk to the police if you're stopped. It will never help you or anyone else.