Google and Apple know where you've been and how long you were there if you carry a phone with one of their operating systems. This is according to Psst! Your phone is snooping on you. What you need to know and how to stop it – video. (Via article of the same title at theguardian.com.)
Most users don't care, otherwise they'd opt out or use different phones. IPhone has a privacy feature which enables the user to refuse to give information to app providers. Unfortunately for Android users, those features are hard wired into the phone's operating system.
How long before NSA gets access to it? Oh wait. They already do.
There's a way to hide your data with a special phone pouch. How does it work? From Detraktor.com:
This is accomplished by having a conductive material encapsulate the device, card or passport. The conductive material acts as a Faraday Cage which shields all RF signals from going into or out of the device or card.
I assume there's a wire mesh inside the pouch. Meanwhile, I'll be making my own tin-foil-hat.
Editor's note: You know they haven't made tin foil in years, don't you? -- Robo-ed | Dammit, I smell a conspiracy! Sleepless.