Thus it is quite clear that Obama is currently using a Galaxy S4. The device is a hardened version of the S4. The camera on the device cannot be opened due to security purposes. It cannot be used to make calls to various pre-determined numbers.
Even text messages cannot be sent from the phone and music playback is also restricted to it. Obama joked that the device was so locked down, that it seemed like an infant’s toy phone.
In other news, people who had bought a locked Galaxy S4 and want to unlock it in order to take it to a different carrier could do so easily. A locked phone comes with certain subsidies and thus users generally opt for it. An unlock code is currently available that will allow them to unlock the device.
To unlock the device users will have to switch it off and put a new sim in it. Then they need to switch it on and dial *#197328640# using the dial-pad. Then the following steps need to be followed-
 UMTS >  Debug Screen >  Phone Control >  Network Lock > Options  Perso SHA256 OFF.
After following the steps, users will have to wait for a few seconds and then go back to the main menu. The Network Unlock option should become visible after this and users can select the  NW Lock NV Data INITIALLIZ option which would unlock their device.
Stay tuned for more updates on Samsung Galaxy S4.