Ok first of all, that server you connected to was probably not a server, but a shared folder running on someone's computer, it could have been the file share used to play movies on the plane.
Second of all, Music copyrights are not ignored. Matter of fact it is a DMCA complaint if it isn't recognized, streaming sites pay royalties to the producers and artists every time a show or song is played, mostly through ad content. If you watch a downloaded movie that you did not pay for and someone else is not playing it for you, you are illegally watching a movie.
Watching a movie on a file share is like going into your neighbors house without permission (just because he left his door unlocked) and watching his movie collection. It's not hard to trace either.
As far as playing movies, you should legally download your movies through whatever offering you have and play them directly from your computer when you have no service. How you can do this is described at your providers website. There are many of them and each are different.
