It was expected 2.5 million households would take up the free porn-blocking filters within 12 months but only 144,088 filter products have been downloaded or ordered on CD-ROM since August last year. The Department of Broadband, Communications and the Digital Economy has estimated about 29,000 of these accessed filter products were still being used - less than 2 per cent of the set target.

"The program has clearly failed, despite over $15 million being spent in advertising to support it," Mr Conroy said. "Labor has always said that PC filtering is not a stand-alone solution to protecting children from online dangers. The Government has a comprehensive cyber-safety plan that includes the implementation of mandatory ISP-based filtering to deliver a filtered feed to all homes, schools and public internet points. "Education for parents and teachers as well as children is a priority."

Mr Conroy said the Australian Communications and Media Authority (ACMA) would examine all aspects of ISP-level filtering, with a laboratory trial completed by the end of June 2008, followed by a pilot test in a real world environment. Sixteen-year-old Tom Wood, aka "The Porn Cracker", who shot to national prominence when he showed the new NetAlert filters could be bypassed by any savvy teenager in a matter of minutes, said the scheme had been a waste of time and money.

"Although these are amongst the best PC-based filters available, it didn't take long for teens to work out how to bypass them," said the schoolboy with a passion for cyber-safety. Opposition communications spokesman Bruce Billson said the Rudd Government was rushing to criticise the NetAlert program to set the scene for a "harebrained, half-baked policy dreamt up in the lead-up to an election". "NetAlert is a program which is relatively new, as is the minister in his role, and I'm sure he would like a little more than six months or so before the public decide if he has been a failure or not," he said.

"Proper supervision should be front and centre of any efforts to protect children from inappropriate material on the internet; supported by additional tools such as content filters, not some mandatory and ill-conceived 'clean feed' measure by a government that believes only it has the authority to decide what's appropriate or inappropriate content for computer users." hgilmore@sunherald.com.au