E-mail anti-spam systems are able to crowdsource and otherwise build up reputation for domains. Surely "selecting the legit domain for Organization X" is within the realm of computability.

Of course, I'll admit there is a danger there of creating a two-tier domain system, where the "big guy$" get the green Checkmark of Legitimacy or whatever in browsers, and everyone else, including mypersonalwebsite.org gets the shaft. I don't have all the answers but surely we are capable of at least crowdsourcing a list of known scam sites and surfacing them at the browser level.