How would you feel if your start-up was ripped off? Would you want HN people to rally around you, or would that be "mob justice"?
And what if it turned out the same people were also ripping off, say, Microsoft and Apple and several other large corporations?
If everyone had been so civil and polite, they wouldn't have felt pressured to shut down.
I don't know about you, but I'll take Facebook comments and phone calls over getting served with papers from half a dozen massive legal departments any day.
Lawsuits are expensive even when you're innocent.
If the penalties are draconian for not even distributing but just "making available" mp3s with NO commercial intentions whatsoever, what do you think the penalties are going to look like for massive distribution of hundreds or thousands of discrete willful infringements for profit?
This so-called mob justice is immeasurably nicer than what the actual legal system would have done to them.