China may be public enemy number one when it comes to internet censorship. But ask executives at Silicon Valley's leading companies about other countries that cause them concern and the first name that springs to many lips may seem surprising: Australia.

In the name of suppressing child pornography, the Labor government of Kevin Rudd, prime minister, has championed the imposition of some of the toughest internet filters proposed by any established democracy. Many internet companies fear that this is just the thin end of the wedge.

David Drummond, Google's chief legal officer who fronted its showdown with the Chinese censors last week, warned recently that Mr Rudd's government has “designs perhaps on things that were offensive to Christianity”, along with other content it deems harmful. The temptation to adopt filters such as this without strict controls “does seem like the slippery slope [in the west] unless we turn things around”, he added.