> > The only thing we have to lose is privacy for domain owners.> This is a huge downside. Anonymous publishing is a very important right.
It also wouldn't work. Or rather, at best it would only work as well as political campaign message attribution does (and that's with considerable enforcement muscle aimed at it).
Somehow "dark money" often manages to evade these efforts, and evade the consequences of violations, and I wouldn't expect transnational phishing and scams to be any different.
Which isn't to say that we should stop trying, but sacrificing the capability of the general public for anonymous speech in return for dubious-at-best attribution by well-heeled actors seems like a poor tradeoff.