How to UNLOCK AN IPHONE WITH FIND MY PHONE LEGALY?

I have an iphone 4s with iOS 7, that i recently founded (i can't find the owner) and it appears to be locked by a activation screen where it asks about an apple id and it's password.

1. Download an unlocking software to your PC for your cell phone's model, such as a NokiaFree Unlock Codes Calculator, Unlock Samsung @ Home or MotoBlaze for Motorola phones. Alternatively, download a universal phone unlock software calculator like Universal Simlock Remover.
2. Navigate your phone's "Status" menu to view your phone's IMEI number. Press "*#06#" on your cell phone keyboard and then press the "Call" or "Enter" button to view your phones IMEI number. Note down the IMEI number.
3. Launch the unlocking software. Double-click on and run the software program to access the software unlock platform.
4. Enter the IMEI number in the IMEI text box provided and click the "Generate Code" button. You are shown a list of unlock codes for your cell phone.
5. Choose your phone's manufacturer, make and model, your country and your cell phone provider from the drop-down list provided.
6. Type one of the unlock codes into your phone to unlock your lost cell phone.