Comment Re:registered-only list. (Score 1) 49
Phone-to-provider encryption seems like a better option. The only unencrypted information to start with would be your provider's ID, so your traffic is routed to their systems for decryption. Basically... my best current guess for greater security? Give up your mobile phone number, use data and a VOIP app. Then the cops will have to get a warrant (assuming your VOIP provider worries about that) not only to know the content of your conversation, but even to know who you called.
You're never going to be able to hide your phone ID and location with current cellular technology, though. You're not connecting to a tower at all unless it knows you're a valid client, and once you connect to a tower they at least know your general direction (most towers have antennas facing each direction, and aren't omnidirectional) and can guess your range. If you hit three or more towers, they can start to approach GPS accuracy pinning you down.
Long before you have to worry about all that, the cops will already have you under surveillance. Every box on every pole around your usual hangouts could be a camera and mic. They could have put devices in your car or home. And I wouldn't bet on them waiting on a warrant to do these things. The warrant will come when they think they'll need to use the information in court and might get called on it.