Online piracy of games and DVDs is widespread, or so I gather. I don’t myself play computer games and I don’t have a DVD player, and furthermore I’m not really the right generation. But considering how music sharing worked in the 70’s and 80’s, I fully believe that it is widespread. Notoriously peer-to-peer networking has been used for this purpose.
Some of the lower forms of life in our society have seen an opportunity in this. They get a firm of unscrupulous lawyers to start sending out letters intended to frighten ordinary people into paying up. Not that the chancers actually know whether the recipient is guilty — the letters are (a) fishing for money, since most people pay rather than be dragged through the courts and (b) fishing for some real information about the recipient. Often all the toerag has is an IP address, obtained from a complaisant ISP. In consequence there have been some juicy tabloid stories, where the chancers accused frail pensioners with no internet access of using p2p and demanded money!
This link from beingthreatened.com contains details of how to respond if you receive a speculative invoice of this kind. It makes interesting reading, and I recommend it.