Satisfactory answers? Yes, there are.
Fundamentally we need to break the economic models used by the scammers. They have actually managed to do that for the stock-market pump-and-dump scammers, and you may have noticed that there is almost no stock market spam these days.
Even though the credit card scams are potentially quite profitable, I think that they are mostly being handled by the banks. Not completely effectively, but there are two important points here. One, there are plenty of laws on the books and we are reading reports of the arrests. Second, the banks are basically obliged to protect the victims from the fraud. If not, people would become too afraid to have credit cards, and the banks certainly don't want to lose that part of their business.
There are new threats from identity fraud, but so far they have not become major problems. Again, I think the economic factors predominate. It's hard to steal an identity that has value that can be converted into cash for the scammer. There's also the problem of coverage by existing fraud laws.
That leaves the old-fashioned email spammers who need those zombots to spew their garbage and sustain the illusion of dividing their costs by zero. Their broken economic model is to throw the very real costs on other people, and if another million spams finds one sucker who sends $27 for herbal viagra, then they think the RoI is infinite. There also seems to be increases in the spam for the old 419 scams.
The best way to break those old economic models is with simple math. There are LOTS of people who hate spam. There are only very FEW suckers who send money to the spammers. We need better tools to let the MANY people get between the spammers and their victims. I firmly believe that Google could do this--except that I also think Google has already become so evil that they've reached a 'comfortable' equilibrium with the spammers.