As a thought experiment, imagine this this: tomorrow, I invent a machine that can make unlimited free copies of soybeans, and distribute those beans instantly to almost any point on the globe, also for free. And also, for the sake of argument, imagine that nearly everyone on earth has access to my soybean copier.
In this case we could fairly say that the supply of soybeans is ~infinite, and you only need to read the first page of the Econ textbook to learn that the price must necessarily fall to zero, no matter what. It's a mathematical certainty for any finite demand.
You can pass whatever laws you want, but so long as they're practically unenforceable, you won't change the boots-on-the-ground spot prices in the market, which will hover very close to zero. (If you doubt me, ask the Argentine currency bureau if legislating prices works well.) Obviously the price will never be exactly zero, because my machine still needs electricity to run, and the market will perhaps price in a little law-enforcement risk. But in general these costs are probably going to be negligible.
And of course this has nothing to do with soybeans---the same thing will happen for corn and light sweet Saudi Crude #2 and intelligence reports about the location of Assad's WMD or any commodity you'd care to name. And digitally copyable goods are the very definition of a commodity, for while not all soybeans come off the vine created equal, a torrented .avi is a provably interchangeable item with the original. Thanks checksums. (If a film ain't on the Pirate Bay, then obviously supply != infinity, so my argument doesn't apply).
This sucks for the business models of the entertainment stakeholders, but capitalism doesn't care that you disagree with the market about the price of your product. Those stakeholders took profits for a long time, playing (approximately) by the rules of the game, and now they're pissed that those same rules have invalidated their business. Well, tough luck, MPAA. The market's invisible hand is slapping you and you'll have to adapt.