ClickZ reports that a Sept. 2004 Google patent covers a variety of Wi-Fi-based ad targeting: The patent, published last week but not yet granted, includes among its claims serving ads based on location, the entity providing the Wi-Fi hotspot, and behavior of a user at a hotspot--and all combinations thereof. They'll have a tough time defending this patent, as there are piles of prior art for delivering ads via splash screens, although perhaps not with the same degree of targeting. They might win some claims or some limited methods of supporting those claims instead of blanket intellectual property ownership of everything in this realm.
Update: News.com reports on two related patents, one for reduced-rate Wi-Fi access and another that would change a browser's appearance to be branded with the hotspot's operator's brand.
I'd agree. Thought that Jim Thompson and his cohorts over at Wayport had a patent or two on that way before google did.