Your phone (GSM anyway) continuously reports back to the cell tower it's connected to, the strength of every other cell tower it can "see". The cell network, not the handset, decides which is the better cell tower for your handset to transfer to, which is why this information is being sent in the first place.
That information, the strength of cell towers, along with the knowledge of exactly where a cell tower is placed, can be used to triangulate your position down to a few meters in crowded areas with many cell towers. It's also how your phone establishes its position without GPS.
Besides that, you probably also have a handful or more apps that tracks your location within 100m constantly.
That's not the point of this thread. The original point is whether there's any desirable mass surveillance. I think we've pretty much shown there isn't.
Your phone (GSM anyway) continuously reports back to the cell tower it's connected to, the strength of every other cell tower it can "see". The cell network, not the handset, decides which is the better cell tower for your handset to transfer to, which is why this information is being sent in the first place.
That information, the strength of cell towers, along with the knowledge of exactly where a cell tower is placed, can be used to triangulate your position down to a few meters in crowded areas with many cell towers. It's also how your phone establishes its position without GPS.
Besides that, you probably also have a handful or more apps that tracks your location within 100m constantly.