But that's Hollywood. It is not book or magazine publishing. In sixteen years of writing fiction professionally I have never heard of an editor taking a submitted story and stealing it. It just does not happen. I'm still concerned.
Publishing is based on trust.
As an author, you are expected to keep your word to the editor. And vice versa. Nearly all editors do. Yes, it can. It can hurt your pocketbook, and it can hurt your chances of getting a story published.