It is a violation if you agree that it is indeed illegal. You do not necessarily have to agree with the laws of your particular country.
For example, the Eightfold Path's notion of "sexual misconduct" is deliberately not specified in detail, as what is considered "misconduct" varies from society to society. For example, in some society it is accepted to have multiple wives, whereby sleeping with another woman does not cause suffering, whereas in another society it does.
I think the true wisdom in all Buddhist precepts and advices lies in the very fact they are open to and welcoming your own honest interpretation.
To say that "illegal downloading" violates the precept per se does not make any sense. Whether or not this is deemed illegal and/or punishable (and maybe there are other qualifications than just these two as well) chances from one government to the next. This would mean that one year you violate a precept and the next year you don't. Don't look to governments, to capitalism, or whatever other system that tries to tell you what to to. Mind you, it has taken a whole lot of breaking precepts to come up with this whole copyright philosophy in the first place.
Is it a violation if a researcher can save millions of lives developing a new drug but violates a patent? Only if the researcher sincerely believes in the patent system. Be true to your own heart. Don't you think that is what the Buddha would have wanted for you as well?