Look, let's ignore the whole "who's fault it was that files are out there" and "is downloading wrong" argument. Under US law it is wrong. Done. But what is it really? For me, if you aren't sharing, it is theft. In this case, it is Petty Theft. From a Californian Defense Lawyers website:
Petty theft involves the taking of property whose value is less than $400. If you are charged and convicted of misdemeanor petty theft, you may be sentenced to up to 6 months in jail and fines ranging from $50- $1,000.
If the value of the property taken is less than $50, you may be charged with a simple infraction. An infraction is less in severity than a misdemeanor and the penalty for infraction petty theft is a fine less than $250.
How you go from petty theft to $1.5 million is beyond me. The US legal system should not allow the music industry to make these sorts of examples.