You really think google doesn't have the capability to create a system to detect these ads? This is Google's core business and they do far more impressive stuff in the AI field. I'm not talking about a 100% bulletproof all-copyright-in-the-world solution. If it would be able to detect logo's from the top 1000 brands and some OCR would already go a very long way. Sure ads would try to outsmart it, just like spam it would be a cat-and-mouse game.