The US Supreme Court is about to decide the digital fate of tens of millions of people around the globe. Everyone who downloads music online, or sells CDs; everyone who markets digital gadgets, or covets an iPod or TiVo; everyone who cherishes free speech on the internet, or would like to muzzle it - all have a stake in the outcome of the most important case of the internet age.

The case is MGM v Grokster - otherwise known as Hollywood vs internet piracy - and it tests the legality of so-called peer-to-peer file sharing, which permits users to share the content of their computers, musical and otherwise. Both sides agree that the case, which will be heard on Tuesday, goes far beyond music. To hear them tell it, the future of technology, the internet and the American economy is at stake.