For example, a lot of cops are so accustomed to asking if they can frisk people, asking if they can search cars, houses or other property, asking people walking down the street to present identification, asking people not to film police activities, asking people to answer a bunch of random questions, and so on, and having most people cooperate with such requests, that a lot of cops now mistakenly believe that they have the legal right to demand such things, and punish any who don't comply.
If someone who claims to act on behalf of authority is never challenged on what he has the legal right to do, he may very quickly get the idea in his head that he has the legal right to do whatever he wants, to whomever he wants, whenever he wants. And that creates a very dangerous situation indeed. Ironically, it is often good people's eagerness to be helpful, open and cooperative that contributes to the formation of totalitarian regimes. If no one ever resists expanding authoritarian control, it will keep right on expanding.