So, in real life, if one violates copyright, one should expect to be served a paper of some sort? This is never covered in "Law & Order" or "CSI", which is where all my legal knowledge comes from. Also, my drug knowledge.
I only watched CSI: Miami. It was one of the funniest shows on television, until I saw an interview and realized it was intentional humor...
Anyway, my understanding is that you could just end up with a summons to show up in court, but the more rational copyright holders contact you informally first, then move to a written (possibly electronic, if feasible) Cease and Desist order, then they go to the judge. That's hypothetical, though. I've never dealt with a situation that went past the first (friendly) step. I suspect this happens, though, because judges are less interested in helping a "wounded party" who couldn't be bothered to assume it was a mistake and ask nicely.
(The new wrinkle are the groups that purchase copyrights to distribute the material so they can find people to shake down. They'll threaten to sue, but offer to take a settlement of a couple thousand dollars. It's popular to do this with pornography, apparently, because the threat isn't so much losing the lawsuit so much as "you'll be in the newspapers for downloading porn.")
The FBI has only ever busted down my door over a copied VHS tape that once. In retrospect, it improved the plot of Highlander II dramatically...
If you're a distributor, and if you didn't bother to show up in court, then there's a fairly good chance that the judge would issue an order to seize the material. That would probably trigger a visit from law enforcement. That happens a lot at the ports over counterfeit merchandise. Which isn't actually counterfeit, in most cases, not only because the term doesn't really make sense, but because a lot of it is factory overrun that was permitted to be sold near the factory but was sent to New York instead. But nobody's ever happy when you bring that up.