Originally Posted by Hellmark
Normally they just invalidate the serial, so the purchaser or anyone else can no longer use it. Legal action is rare, because you have to prove they did it. Doubt gets introduced if anyone else has access to their things or computer, making it an uphill battle. Just like if a car is used in a crime, you cannot just charge the owner with the crime. (Before you mention speed cameras and traffic light cameras, their legality is in dispute in many areas for this reason)
Yep. Will the same occur when copies of watermarked books appear though? It's become increasingly common for people to receive letters with flimsy evidence saying pay X or we take you to court (for downloaders based on IP), the same could apply to the source of any book, will anyone want to risk the cost of going to court to show they didn't upload it?