Here is a very interesting question. We all know it is illegal to borrow DVDs, copy them (either to another DVD or your hard drive). Okay, that's fine. However, take the rare occurrence where you are reasonable and only backup DVDs you own. Now say you lose the original copies somehow--moving, weather, whatever. Now, you have a nice pile of DVDs on your hard drive--which you kept offsite so it's safe--but, you don't really have much if any proof that you actually purchased a copy of those titles. This all assumes that someone would question you.
Besides, what would be the procedure for "getting in trouble for doing something like copying friends DVDs while borrowing them?" I don't support illegal activities like that but have always wondered that! Does a RIAA or MPAA official have to walk into your house and examine your computer? Does a police officer have to? How could you even get caught? If you got in trouble for something else and police searched your computer, finding lots of ripped movies/music, what could they do? What if they didn't even check to see if you own a copy on DVD--they just assumed you got the content illegally?
interesting, hmm?
Addition: I really like ripping my DVDs because it just makes watching them SO much easier. I watch a limited number of movies and the process of actually deciding to watch one is usually somewhat random. With my main computer, our living room computer, our family room computer (with 31" monitor), my laptop, or best yet--our theater (projector--130" screen) I can just call up MC with all my DVDs ready to go and I'm watching the movie in a matter of seconds! Compare that to deciding a place to store our DVDs as central as possible and then the likelihood that DVDs would get moved around the house, misplaced, lost, damaged, or not put away when finished. All those things literally destroy the few chances I actually have to watch a movie. I also love the ability to instantly pull up a portion of any movie...if a song comes to mind in a movie, I've got it in seconds! The only delay, other than human slowness, is the time it takes for the hard drive heads to locate the precious DVD VOBs.