Google has also done some foundational research on learning with privacy: https://arxiv.org/abs/1610.05755 https://arxiv.org/abs/1610.05755 https://research.g

Google has also done some foundational research on learning with privacy: https://arxiv.org/abs/1610.05755 https://arxiv.org/abs/1610.05755 https://research.google.com/pubs/pub45428.html https://research.google.com/pubs/pub45428.html It's hard to know for sure what they (or any company) are doing in production, but I'd be surprised if they don't use these things internally.