> It ought to be illegal to buy ads against trademarks (+/- some reasonable edit distance).

I get the intention here, but how do you limit the collateral damage? (Or do you not care about it / see reducing the ability to advertise as a positive?)

There are a lot of trademarks, and they have to be scoped to specific goods and services, but Google has no way of knowing if you're actually looking for something related to that trademark.

e.g. doing a quick trademark search, I see active, registered trademarks for "elevator", "tower", "collision", "cancer sucks", "steve's", "local", "best", "bus", "eco", "panel", "motherboard", "grass", etc. etc. I'm not familiar with any of those brands, but that's just a small sample of the fairly generic terms that would no longer be able to be advertised on.