Soon to come out of the US Supreme Court is a decision on MGM vs Grokster. In short, MGM says Grokster should be held liable for folks who violate copyright law using Grokster's service/software, and Grokster says they shouldn't, since they have no direct control over the files traded on their system.
Apart from the fact that I've obviously been interested in copyright issues recently, this case shows why I've long been fascinated by Supreme Court cases. In many of them, including this one, there isn't a clear, cut and dried solution to the issue.
On MGM's side, the law says "don't copy without permission". So MGM is properly upset that so much of their stuff gets copied w/o permission over Grokster. But on the other side, we've rarely held a manufacturer responsible for things done with their stuff, as long as their stuff works as it should, and has significant legal uses. Gun makers immediately come to mind. Grokster supporters rightly say an MGM win would give content companies veto power over any new technology that they don't like, which would put a big chill over innovation of every kind.
It's widely expected that the loser will make a mad dash to Congress and try to buy, er, lobby for new legislation in their behalf. A decision in this case is expected sometime this month.