I have a firewall on my phone, I don't let it talk to 1e100.net (google) or facebook or amazonaws (have to allow this sometimes unfortunately since everything uses it) or a few others. It's a bit of a pain in the bum and I honestly don't know if it does anything really, but I see all the thousands of constant attempts to connect to these servers so I guess it's at least probably stopping a bunch of this sort of low-level spying?