@FritzAdalis @GossiTheDog Oh, they care a lot, because it goes directly to the bottom line.
But eliminating all malware is functionally impossible at their scale, especially when every server that those ads link to is allowed to do a Turring-complete analysis of the request packet to craft a tailored response. It's about the same complexity of difficulty as eliminating all viruses from Windows during the heyday of those exploit vectors.