"But I also know if I can get music without buying it, I'm going to do so."

So said Justice Souter -- of all people -- in the oral argument in the Grokster case today. Doesn't look too good for the music industry side, does it?

But by the end of the lively argument pitting Grokster and its allies on the electronic frontier against the entertainment community's stalwart defense of intellectual property rights, any prediction about what the court will actually decide appeared perilous.

It's a difficult case, and the question, based on the old Sony case about videotaping, is whether there's a "substantial noninfringing use" for the technology:

Justice Antonin Scalia said he was concerned that legitimate uses of a new technology might need some time to become established; in the meantime, the developer would be defenseless against a copyright infringement suit. "What I worry about is a suit right out of the box," he said. "Do you give a company a couple of years to show 'substantial' noninfringement?"

[Acting Solicitor General] Clement replied that in the government's view, there should be "a lot of leeway at the beginning." But that was "not this case," he said, asserting that Grokster and StreamCast had "a business plan from Day 1 to capitalize on Napster."

See? It's really difficult!