It seems a decent compromise. I mean, there's no way that investigators would get totally locked out of cell-site location data. For those concerned about their privacy, the best option is keeping devices off, in Faraday bags, except when in use. So you get to pick which locations get reported. You're less reachable, but that's the necessary tradeoff. And for long-term storage in Faraday bags, it's important to remove the battery, because otherwise the device may drain it, trying to ping towers, even though "turned off". Alternately, you could just nuke the radio, use only VoIP via WiFi, and disable GPS location capability. That was Mike Perry's old advice. But even that's not very reliable, given difficulty controlling apps. And because there are multiple software levels, most of which aren't user controllable. However, even if all that works, you don't really have a "phone" anymore. Just a small portable computer.
