ACTUALLY, the Berne Convention pretty CLEARLY stipulates that only the copyright laws of the country that an individual is IN applies to the individual. Though, it is worth noting that the Berne Convention does set MINIMUM STANDARDS in copyright law that all signatory nations must include. And beofre you look it up, literally every country that matters is a signatory of the Berne Convention.
So for example, me as a Canadian, only CANADIAN copyright law applies to me even if it involves AMERICAN copyrighted works. In Canada copyright expires after 50 years where as it expires after 70 years in the United States. There are American creative works that are PUBLIC DOMAIN in Canada but even if they are still under copyright in the United States itself.
However, AGAIN, we are talking about INDIVIDUALS pirating materials. Huge, big money, complex cases like MegaUpload and Kim Dot Com are an entirely different and monstrously complicated animal all together.