Florimond Houssiau, Luc Rocher, and Yves-Alexandre de Montjoye show in this short paper that the privacy guarantees given by Google for their shared aggregated data from 300M Google Maps users to be incorrect.
New Nature Communication paper: “On the difficulty of achieving Differential Privacy in practice: user-level guarantees in aggregate location data”
Florimond Houssiau, Luc Rocher and Yves-Alexandre de Montjoye