as to this particular issue of itunes and such...this is why that, since youtube started allowing full movies to be posted, and there are sites where some post links to them, that they are often gone quickly by way of the particular movie company having them removed from youtube...
they don't, of course, catch all of them, nor do I expect they think they will either, but they catch some of the obvious ones via that channel of dissemination...
which is why when i go to watch one of those movies they are often removed while i am watching them, usually at the best part where some cool thing is happening and i get very annoyed!!!