No. You cannot legally argue theft. The stepfather did not steal the phone - he confiscated property from his minor stepdaughter.
This is a disciplinary action and it is permitted. You can ask the stepfather to return the phone to you. If you promise to leave the underage girl alone, he might even give it to you.
I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.