A good rule is to let the caller decide. If input parameters are by-reference and the caller wants to make them by-reference, congrats, no problem. If caller wants the parameters to by a copy, they can create a clone and pass a reference. But if you impose the input parameters to by copy, there's no way back.
yeah of course, I'm all for a guaranteed minimum income. I guess you are going to do a kickstarter right? I hope you are not proposing to forcefully steal my money through taxes.
There's no paradox in Amazon. The antitrust law makes no sense. The people will decide collectively and distributedly (= the market, a p2p network) if they like Amazon or not. There is a conceptual error in the idea of needing the government to interfere the market with these antitrust laws.