Location data is a valuable commodity, both to consumers and to businesses as they connect with each other. Location services have become an integral part of the smartphone experience, but the other edge of the sword is how location services can track users. The major carriers long ago realized the value of this data and have been selling it, even as calls for a federal investigation mount. We aren't even touching on the subject of what the government could do with this data either.
The value provided by location services to consumers can not be overlooked though. A large part of the power of having a computer in your pocket comes from that computer knowing where you are and where you go, this helps in navigation you and in making meaningful suggestions for you. Turning off location services entirely definitely cripples the user experience.
First, in iOS, location services uses what they call Significant Locations, which allows for useful information in Maps, Photos and Calendar apps. From Settings, go to System Preferences, Privacy, Location Services then finally Significant Locations. You'll be prompted to authenticate, then you will see all the all the locations you've been to, grouped by city. You can clear out specific locations within a city but you can not clear only one city. To do that you must Clear History, which is at the bottom of the list of cities, and will clear all cities. This isn't ideal but it's the state of iOS at the moment.
If you have Share My Location turned on in your Location Services settings, you can select which device from which location will be shared. Select Share My Location and you will see the option to share it from other devices that are using your Apple ID. For this, I have my old iPhone at home anchored to a wall outlet, and I use that device for this purpose. This gives you some control over what location you share, and you could place the alternate device at any location that is convenient for you.
Depending on how far you want to go, you can thwart Location Services by hiding in the services that it uses. Location services runs the gamut here, it uses GPS, Bluetooth, WiFi and cellular tower data. For GPS, there are GPS faking apps on the app store. To turn off cellular data, go to Settings then Cellular and un-select Cellular Data. Bluetooth can easily be disabled from the Settings. WiFi is a special case. You can always turn it off in the settings but it could still use crowd-sourced data from hotspots, so the best way would be to use a VPN and literally route your WiFi traffic to another location. Any combination of these can be used, or all of them if you are hell bent on not being tracked. In such a scenario, I would recommend turning off Bluetooth and cellular data, using one of the GPS faking apps, and using WiFi while being connected to a VPN for which you own and control.
--Jay E. blogging for digitalinfinity.org