Devices, SIM cards and identities must be matched in Turkey, so that nobody does anything naughty. They also make the service providers keep tower signal logs worth of many years, so it's common to prove your whereabouts in courts by requesting these logs.

On the plus side, you can see and manage all your data from the government portal. It's rather convenient to be able to see all the subscriptions(GSM, TV and so on) on your name and cancel them from there if you wish. Totalitarian control has its perks.