> The ideal privacy respecting weather app would download and update a local copy of every location's weather, You can also do it with multiple, independently

> The ideal privacy respecting weather app would download and update a local copy of every location's weather, You can also do it with multiple, independently operated servers, as long as they don't collude with each other beyond a given threshold. Then the queries and responses can be kept small. The private info in the queries is split between the servers, and the responses are recombined, using methods inspired by Shamir secret sharing in cryptography. That prevents the servers from learning the actual queries being made or responses being sent. See: https://en.wikipedia.org/wiki/Private_information_retrieval#Advances_in_information_theoretic_PIR https://en.wikipedia.org/wiki/Private_information_retrieval#...