This is a topic that I'm sure can attract a lot of debate.
For me, downloading something illegally can be considered stealing. At least by law it is stealing. Many sharing sites are being shut down because what they do is considered illegal. But then again maybe the motivation behind it also determines whether you are breaking your vows. If your motivation is solely to steal from them, resell their movies and make money from nothing, then I am quite sure that this would break your vows.
But if we are downloading to a film, or music with someone to help them, by helping them relax, by helping them learn something good; then it would be a different motivation and perhaps it would not be considered stealing, but sharing.
In my world, the western world, illegal downloading is a criminal offense and you can be fined for it, if not go to jail. However I have heard in the asian world, many people do this and get away with it.
In my opinion there is no clear and cut answer as to whether you will break your vows. It is stealing in some ways, but in a very indirect aspect. And in some ways it is not stealing, because it is available for free, for you to download. It it said that for you to complete the act of stealing, you must have the motivation to steal, the act of trying to steal, the success of the theft, and the rejoicing of your action. I don't see all these steps in illegal downloading.
Let me know what you think. I am interested to know.