Australian Web site owners are being urged to mark Australia Day (January 26th) with an online blackout to protest against planned compulsory Internet filtering.The federal government’s proposed legislation would force Internet service providers to block access to Web sites on a government-created blacklist. The Rudd government says it is targeting undesirable content, such as child pornography.Opponents of the law say it will cost millions, it won’t work, and will create a centralised censorship regime similar to that imposed in countries like China and Iran. It’s also claimed that sites about controversial (as opposed to pornographic) subjects, such as euthanasia, could be blocked under the law.The campaign, running from January 25th-29th, advises Web site owners how to ‘black out’ their sites for the duration of the protest. The ‘blackout’ can be removed by users with a single click. You can read more about the blackout here.