However another argument: If 99% of the people thought that every 18 year old female must be raped repeatedly until shes 19, will that make it right? A lesser example. If every man believed that a woman must be whipped in public for not wearing the appropriate clothing, is it right? If every man believed that a woman cheating on her husband is grounds for execution, while a husband cheating on his wife is completely acceptable. Is all that moral or right? Consensus does not mean morality.
I feel that InclinedPlane's points raise the correct questions: What part of "piracy" is what people feel is sharing/socially acceptable behaviors taken from the physical to the digital world, and what part is really theft. Intent is important. And how do we separate the theft intent from the sharing intent.
Also another point: Perceived value. If by now people perceive music as worthless commodities, to them downloading it illegally is moral BECAUSE they feel that buying it is a rip off. They are buying something of no value. This could be a side-effect of theft they committed in the past. The content industry must change from "steal and we'll fucking sue" to "steal and you will miss out on big values of the product"