Today was a very big day for technology at the U.S. Supreme Court, with two hugely significant cases being argued. The first, Grockster v. MGM Studios, arises from the movie and recording industries’ efforts to impose contributory copyright infringement liability on post-Napster providers of P2P file sharing software. Supreme Court Takes Hard Look at P2P [CNET News.com]. The second, BrandX v. FCC, arises from the FCC’s efforts to clear the way for cable modem broadband service without requiring cable companies to share their facilities with ISPs. Supreme Court Asks Why Cable Broadband Lacks Regulation [ITWorld.com].

It’s always hard to predict where the Court will come down from its oral argument questions. But these remarks from Justices Breyer, Scalia and Souter in Grockster are quite revealing.

Justice Stephen Breyer pointed out Xerox copiers, videocassette recorders, iPod music players, and even the Gutenberg press had the potential of abuse by consumers. “In each case there could be vast numbers of infringement illegal uses,” he said, but he added that the benefits to society from those inventions were incalculable.

Justice Antonin Scalia wondered whether innovators would be punished immediately after creating a new product if the entertainment industry had a legal veto. “If I started a business now, how do I know how to proceed?” he asked. “If I’m a new inventor, I’m going to get sued right away.”

“There’s never the intent to break the law when the guy is in the garage inventing the iPod,” added Justice David Souter.

There’s a sense to which both the cable and entertainment industries are overreaching. I’ve got friends and colleagues on both sides of each of these issues, but biting off more than one can legitimately chew is a very bad strategy, since courts (especialy the Supreme Court) are pretty good at sorting out litgants who overstate or overplay their hands.