Why?
Effective Altruism can't be fully effective if it can't spot scammers.
Yes this is hard, yes extra hard when the first encounter is them parachuting a promise of a billion dollars into your lap… but while I have no solutions and absolutely don't blame anyone who took that money, it's not dumb to criticise.
In fact, I'd say that failures you couldn't spot in advance are the learning opportunities; failures you did spot in advance would make you a co-conspirator in my view, even if not by law.