What I don't understand is why it's an opt-out not opt-in. From a legal standpoint, it seems if there is an option to not have something done to you, it should

What I don't understand is why it's an opt-out not opt-in. From a legal standpoint, it seems if there is an option to not have something done to you, it should be the default. For example, people don't have to opt-out of giving me all their money when they pass by my house, even if I were to try to claim it's part of my terms of service.