I got this question recently:
“Years ago I took a screenwriting class at a community college. I wrote a synopsis and 30 pages of my screenplay. As students of the class we had to share our stories with the teacher and with each other for critique and advice. My story was very personal and unique, it is based on my true life experiences. I had never seen or heard of a movie about my subject matter. Now present day a new movie released this year, is about the same subject matter as my story and a lot of the details and circumstances are the same, when I saw the trailer it looked like I was watching a trailer of my synopsis. WHAT CAN I DO? Can I find out where they got their idea? Was it from my community college synopsis? Should I try to have my movie made? Will I be accused of copying if I present my story?”
Without knowing any of the details of your specific story I am 99.9999999999999999999999999999999999999999999999999999999% sure that no one stole your story idea. Look at it from the producers standpoint. It’s much easier to pay a writer for their idea than to try and steal it and face a lawsuit later. Forget about the morality of stealing an idea it just wouldn’t make good business sense.
I find that new writers tend to greatly over value their ideas. A screenplay is not one or two great ideas, it’s lots and lots of ideas executed in a very specific fashion. A lot of simple ideas that new writers have are not nearly as original or unique as they think and they’re not even copyrightable because they’re not new or novel. Just because you never heard of a specific idea doesn’t mean that someone didn’t think of it independently of yourself. We’re all basically the same living in essentially the same world, so ideas are bound to overlap.
The good news is that your original idea appears to be marketable so you might have good instincts for strong marketable story ideas. I would encourage you to continue to come up with ideas and turn them into fully fleshed out screenplays.
Now with all that said, I would encourage you to go and watch the movie. If after seeing the entire movie you are still convinced that someone stole your idea you should start to do some basic research. Start with the writer. Who got writing credit for this film? Did that writer grow up in similar circumstances as you did so that he might produce a story that is similar to your own? Or was that writer simply in your community college class? Do as much research as you can and if you’re still convinced that they stole your idea talk to an entertainment attorney. Stealing is wrong and it’s illegal and if someone really did steal your story you might have a legitimate case against them. A good entertainment attorney can advise you further.