Public attitudes to file sharing will be crucial (Image: Olivier Morin/AFP/Getty)

“THIS is the kind of snooping you’d expect in China, not a modern western democracy. It raises huge questions over privacy invasion and freedom of expression.” So says Andrew Heaney – who is not, as you might imagine, a civil liberties campaigner, but a senior executive at TalkTalk, one of the UK’s largest internet service providers. Along with other ISPs, his company faces the prospect of being forced to spy on its customers’ downloads for signs of potential copyright infringement.

Heaney’s disquiet is shared by web campaigners worldwide, as the measures contained in a …