A friend of mine had her computer kidnapped by some adware program. She accidentally got the unwanted program from azlyrics.com, which hosts the adware. (Hint: NEVER go to a lyrics site, which is where most teenagers get these things and wind up with non-functioning computers.)
It's a pretty big problem. The adware makers aren't going away, but we can reduce their profitability if there was a list of the sites that host adware. Why isn't there such a site?
So here's an idea for a internet app that shouldn't be too hard to write.
Just as anti-spam software curtails spam by stopping it before it comes in, why not have a list of adware-hosting sites in XML format at, say, Microsoft or Google, and browsers can allow users to prohibit going to such sites if they're on the list? Once the site prove that they no longer host such malware, they can come off the list.
I expect that if such an add-in were available, it would be the fastest-selling app for the next two years. And I expect that the malware producers would eventually wither up.