Cookies, identifiers and other data that google silently stores on android handsets

It is known that cookies and other data can be used to track user activity and infringe privacy, but most work to date has focussed on the cookies stored by web browsers rather than by other mobile apps. We report on the results of a measurement study investigating the cookies, identifiers and other data stored on Android handsets by Google Play Services, the Google Play store and other pre-installed Google apps. We decrypt handset network traffic and analyse the data stored on the handset disk. We find that multiple cookies and identifiers are sent by Google servers and stored on the handset, even when no Google apps have ever been opened by the user. This includes advertising analytics/tracking cookies, links and device identifiers. No consent is sought for storing any of this data and there is no opt out. Our measurements raise concerns that Google is violating EU data privacy regulations, which generally require specific, informed and unambiguous user consent before data can be stored on a handset.