The basis of ownership is reasonably expectation of control.
When Disney releases a film in digital format to the public, they cannot reasonably expect to prevent it from being ripped to torrents. No known technological barrier or feasible policing barrier can prevent this from occurring, and indeed the empirical evidence is that nobody has managed to do so.
Thus Disney is knowingly relinquishing their reasonable expectation, and is therefore relinquishing any logical reason they own the film. You cannot, therefore, steal it.
Of course, I Accept my Ignorance; it is possible that in the future a second valid construction of property rights may be found, and this definition may allow Disney to claim ownership. However, until that time, it is unreasonable for Disney to claim ownership; there is no reason to respect this claim over an insane person claiming to own the sun.
For illustration, consider hard copies.
Taking a DVD from a store is theft, but only because the store can reasonably expect to control the DVD itself. In addition, removing that DVD requires (usually) that the store replace the DVD, and that harms the store directly.
Conversely, you can copy a Disney movie and infinite number of times without them noticing a thing. (Let's not bring up distribution yet, it will just get messy.) Violating a patent is qualitatively different than damaging any kind of real property.
Effectively, everyone with a computer has a data factory, and everyone with the internet has a data logistics network. The computer is like a magic factory. For a certain class of goods, given even one, it can create an unending river of copies, using only a minimal amount of electricity. (Imagine what this would be like with, say, condoms.) And with the internet, you can give these copies to basically anyone in the world for the price of the line. (With condoms, you could send a condom to copy to anyone who also has the magic factory. And here you can see how strange software is compared to hardware; only people who also have the factory can use the condom copies.)
The actual risk-adjusted capital cost of creating copies of Disney movies is almost zero. Because Disney charges a lot more than this, the laws of economics guarantee a black market will spring up.
Disney attempting to preserve their patent/copyright at this point is like someone tossing a steak in front of a bunch of hungry dogs and telling them very sternly not to eat it. Even if it were wrong, it would be a very stupid thing to do.
And actually, this is an excellent case study of why neither prohibition nor monopolies work. Attempting to prevent people from producing valuable things is just dumb. The market is smarter than you are, because you are only one person but The Free Market is People.