I'm a first grade lego thief
Why would you steal from young children?
I believe children should learn that it's a jungle out there. You have a choice between two options: A) Eat or B) Be eaten.
I think that makes you just as bad as other kids. You shouldn't take things that don't belong to you. I would leave their things alone and let them work things out for themselves.
Kids should learn that everyone is out to get their toys and stealing is the only way to survive. They should be more cunning and in for the kill.
Imaging the world where everyone behaved the way you recommend. It wouldn't be a very pleasant place to live. You wouldn't be safe anywhere; everyone would be living in fortified bunkers.