[woozyolliew]

This seems like a potential use-case for differential privacy. Normally DP is used for protecting individuals within aggregates, but the careful analysis of how much (and what kind) of noise to add could be brought to bear here.

[mirker]

It’s only a partial solution; you still need to limit the queries. Otherwise, just sample a large number of coordinates and average out the noise.

[pageandrew]

What about a constant, random, per-match offset? An error applied to a match's position that can't be averaged out, because it is always wrong by the exact same amount. Use a different error in a different direction for each unique match so one can't figure it out once and apply it system wide.

I suppose the downside is that this could put someone else at risk if the tweaked position happens to be on top of their house.

[sa1]

Apple’s coarse location, iirc, chooses your location in such a manner that it can’t be averaged out. Maybe by limiting updates as well?

[dragonwriter]

Yeah, its an overcomplicated, breakable solution. Just decide the minimum safe uncertainty, assign grid cells that provide it, and only report distance quantized to grid cells.

[nprateem]

I can't see a problem with adding a random, static offset to users' locations that is rotated daily.