Their backyard faces ours. Earlier in the spring we met them when we were out playing with the kids and they mentioned that they wanted to host neighborhood movie nights in the summer. Apparently they had a projector a really cool outdoor screen.
Anyway, I glanced out and saw they had started their movie it was packed and then I saw it was Inside Out. At first I thought it was just a preview and then realized it was the actual movie.
My opinion is that you need to mind your own business. What happens in the privacy of one's own home and YARD should remain
private, unless one is in the act of endangering the lives of others and those participating is done non-consensually. They sent a flyer inviting you. You declined. Should have been the end of story.
In some states (still) there are laws that make certain gay *** acts illegal. Would you have called the police on neighbors doing that, if you happened to see into their bedroom window because they didn't have their blinds closed? IF they invited other people into their private home or yard for a private *** party, and you did not partake, it then becomes their private business.
Some places still have laws making it illegal to back out of one's driveway. People are doing it and are not being turned in by neighbors.
Wouldn't the activities you described in your OP make YOU a peeping tom or a voyeur? Once you declined the invitation, it is no longer your business. Just because you can see into the private yard of a neighbor and post the details about it on a publicly Googleable forum doesn't make it morally right either. You should buy heavier curtains, close the ones you have or get tall bushes or a fence to block off the view so YOU do not continue to peer into their yard and publicly posting about them.
I wouldn't do anything. Believe it or not, there are actually legal ways they could have gotten it anyway. Just because it's a movie that happens to be in the theater doesn't mean they're doing something illegal.
Yes, a friend of mine was on the SAG Awards nominating committee one year. She was sent legal DVD screeners way before the ones released to the public. Some were being sent to her starting in the summer. She invited me and and some other friends over to watch and get all our opinions before she had to vote the following January(?)
I would report them, too. They are totally breaking the law and stealing from my very company.
Wow I'd love a listing of what all of you do for a living. And then I'll go and steal whatever it is you make and see how you feel. I worked my behind off on Inside Out.
Again, theft is theft. A poster here was totally wrong in saying that the actors and others were paid for their work. Yes, they were. But what about the rest of us? Some of us can be laid off if a good movie doesn't do well at the box office. For each person that saw this movie, that's $x dollars out of the studio's pocket. Piracy is no laughing matter in my industry. More and more movies are being stolen such that we have task forces now. Where did you say you lived, OP?
Oh, and screeners? Yeah, not for public viewing unless you have written permission.
I understand how very personal this is to you. I understand what you are saying. I've been on many live award show party threads in which a film you or your costume designer friends were nominated for and we all collectively rooted for them to win, on your behalf, or celebrated the wins with you.
But, I still believe that what one does in the
privacy of one's home & yard is their own business. I don't consider someone's backyard as
public viewing.
I grew up in the days of cassette recorders and VCR recorders. We recorded songs playing on the radio or on TV all the time to have on cassettes or vhs tapes to watch later, in the privacy of our own homes or play in our cars.
We didn't sell the copies. And many of us attended backyard parties while listening to those copied songs playing in the background on a cassette boombox.
I have friends who are actors. We often go over at a later time and watch a TV show or film they are in, from a copy they made of themselves in the show or film. We don't wait for the official DVDs of the season or film to watch the episode or film they are in.
Many clips posted on Youtube are posted without copyright permission with the trite disclaimer, "No copyright infringement intended," even though, yeah, they do intend it, and know they are doing it.
Oh, and we are often not supposed to make photocopies of some printed materials. Nor should we be taking pictures of some things - artwork, performances our kids are in - to have to privately look at later. All that is some type of copyright infringement.
So ALL of us who have done any of that belong in prison then.
Are all those offenses I mentioned illegal? Yes. Should people be prosecuted and thrown in prison for them? In my opinion: No.
When they get through arresting all of our generation, you'd better have your bags packed to move to Canada or actually somewhere that the US doesn't have extradition agreements. 
