I can see there being perfectly legitimate(apart from in a legal sense) reasons for having DRM, for after all making movies or music cost money; in investment, time and effort; let alone people don't invest money to just break even, and, if you don't want to pay the money for something you don't have to buy it (or should i say have it!). The problem I feel with DRM and for that matter any other similar system is it that it will make it the only "legal" way to watch a movie or listen to music. This HD format war that is going on at the moment makes me think of never buying a hard copy item again (because whatever format you buy, you either won't be able to get all the movies and/or they'll be another format in 10 years or so, and discs take up so much room!) But I become unstuck when I want to legally buy a digital legal copy. I'd have to use a windows os (which basically means using a windows pc) or maybe a mac, both of which are basically monopolies and in bed with each other (cartel) (while i'm having a rant i recently thought of buying a mac, or maybe os x, until looking into it and realising that i'd have to pay a good 500% mark up on what would be the same spec pc with WINDOWS! (and they've already got a mark up!) and for that matter installing os x on a non mac computer is (i think) illegal!).
So I'll get to my point...using DRM is going to cause (in fact I think u could say already has, and i'm sure most people reading this are well aware) much the same situation with having to use windows/osx, you'll have to buy off the internet sites that are owned/"in bed with" each other because studios won't release the films to anyone who isn't using DRM. Which means you'll either have to pay an overly marked up price or not watch it at all, and for that matter be forced to use other equipment which may not be your preference in order to do so, which has been pointed as being an infringement of consumer rights. Which is kinda where we are at the moment, but it is a great shame as with the huge market of the internet there is still a huge possiblity for companies/film producers/music producers to make large profits buy selling their products with a mind for wide distrubution/low price (like daily newspapers). Which individual consumers would not feel hard done by with.
So.. that was a rather long winded way of saying I think if you wanting to stop DRM then legal action against film distrubutors/companys in terms of creating a cartel could maybe one route.

thanks for reading, that was very therapeutic to write that, I think I have more of an idea of my opinion now ! :)