Colour me cynical, but I'd not be too surprised if a lot of this background chatter is facilitated by that 800ln gorilla that is Google Play Services. It's also the service that has unfettered permissions, can even grant itself permissions, and tends to ignore other preferences/settings.
Aside: Google pushed a broken Play Services update onto my phone a fortnight ago (not the first time this has happened) resulting in it (PS) crashing every 10min. So I uninstalled all updates (reverting to firmware version). Other Google apps, e.g. Maps, Hangouts, Newreader, started bleating that I needed to update PS. Most of those I don't/haven't used. Seems they've all been running regardless? Some third party apps also complained, but appeared to still work fine.
PS: Wish I could uninstall Google bloatware---moreso for Gapps/Gservices that aren't available in my neck of the woods.