This is far less than nonsense: Google partnered with Sonos explicitly to get access to their internal designs, and then copied them. This is closer to industrial espionage than inadvertently stumbling across patent infringement.
> Google partnered with Sonos explicitly to get access to their internal designs, and then copied them
If anything this ought to be strong evidence that the patents failed to disclose the invention and are invalid. Patents are a deal where you publicly disclose your invention in exchange for a temporary monopoly. If someone has to get access to your internal designs to copy them, they shouldn't be protected by patent.
Edit: (Note I'm talking about how the law ought to work, I'm not claiming this is strong evidence under current US law that the patents actually are invalid)
A recipe isn't patentable on its own, though. For most inventions you either need to demonstrate you have already built the thing, or have provided the thing to the PTO along with the application. For software, though, it seems you don't need to do either.
While it's true that Google partnered with Sonos and then copied the features they saw Sonos having success with I'm not aware of any allegations they used internal Sonos documents.
If that happened I'm surprised that no case summaries mentioned this anywhere!
If they were proper partners I would think they would be working together using Google's money along with Sonos patents as a team without needing to license the patent except to those other than the partnership.
I'm not very well informed but it looks like Google was simply an untrustworthy partner and they split up unamicably.
