Say someone takes something from your own house and you notice it happening. If they play stupid or refuse to give it back, can you forcefully take it back, even if it means hitting them, without getting in trouble? I mean, what are you supposed to do... let them leave knowing 100% that they stole something of yours and then call the cops? Not only would that take way too long, giving the thief time to hide/dispose of what they stole, but it'd just be a huge pain in the ass. And you never might get your shit back.