It isn’t always illegal, but it isn’t always legal, either. It depends (among other things, on whether what you’re ripping is copy-protected). There’s some discussion and links in this thread:
I use Plex, which is a media server that allows me to watch movies and listen to music that I own (which is to say, I have the associated files stored on my computer) from anywhere. I use it almost exclusively for music, which are files I have ripped from CDs that I own or files that I’ve purchased digitally through Amazon, for example. However, as I’m thinking about buying some movies, it seems like all the digital versions are streamable only. Is there a way to buy a digital movie and have t…