Either that, or make the networks directly responsible for the content they're serving. I don't understand why that's not the case now, if websites allow downloading of copyrighted work without authorization, or distribute illegal digital goods, they're held accountable. What makes ad networks invulnerable to this?
In the first case they're held accountable because business interests are compromised. In the second, no business interest is compromised by screwing up Joe Public's computer (except Joe's, but he has no material social leverage, so...). Thus no accountability for ad networks, even if there logically and legally should be.
