Paranoia is such a strong word. But I sometimes wonder whether “systematised delusions of a persecutory nature” do permeate the ranks of those most virulently opposed to the Australian government’s internet censorship policies.

On Monday Crikey ran a tip from an eagle-eyed government web watcher:

“ACMA has been submitting a truckload of content to the classification board over the past few weeks with a new naming sequence. Most have come back RC with the occasional MA, R and even a G rating. The applicant is listed as “ACMA — ISP FILTERING”. The mandatory-voluntary ISP filtering of the Interpol list — as Crikey recently reported — started around the same time. “Although,” our reader says, “correlation does not imply causation.”

Indeed it does not.

Both activities derive from the same thread of government policy, but they’re entirely separate.

“Any ACMA list of child abuse material URLs is separate from an Interpol list,” an ACMA spokesperson told Crikey.

That hasn’t stopped the discussions at Whirlpool putting together two and two and coming up with several billion. Hence the P-word.

A year ago, when communications minister Senator Stephen Conroy deftly flipped the controversial mandatory filter into the distant future, politically speaking, he encouraged internet service providers to conduct their own “voluntary” filtering of child abuse material until such time as the mandatory system could be implemented. Telstra, Optus and Primus volunteered on day one.

Blocking such child exploitation material from view should hardly be controversial. There are, however, solid arguments that any attempts to block access will inevitably fail — that’s obvious to a competent network administrator — and that in any event it will do little to prevent the actual exploitation of children. But we’ve been through that before. So. Many. Times.

The material to be “voluntarily” filtered would be that subset of the blacklist of prohibited internet content compiled by ACMA that represented Refused Classification (RC) child abuse material.

As Conroy keeps reminding us, the blacklist isn’t new. ACMA has been compiling it for a decade and distributing it to the makers of internet content filtering software and devices.

“As is required under legislation, the ACMA continues to submit potential prohibited content for formal classification to the Classification Board when the content is hosted in Australia,” ACMA said. Prohibited content earns the hosting provider a takedown notice.

“The ACMA also continues to submit potential prohibited content for formal classification where the content is hosted overseas and is of a threshold nature (i.e. it is borderline in terms of classification or age issues).”

No ISP has started to filter against the ACMA blacklist yet. “The ACMA has not, as yet, distributed any list of child abuse material to ISPs, they said. However Conroy’s announcement “foreshadows a role for the ACMA in terms of distribution of a list of child abuse material and transparency and accountability measures”, so like good public servants they’re doing the preparatory work. That includes continuing to get material classified.

Meanwhile, the Internet Industry Association (IIA) has been working on its own voluntary filtering scheme, both the fulfil Conroy’s request for volunteers and, presumably, to help forestall the imposition of any mandatory scheme.

They chose the Interpol blacklist, which is compiled according to Interpol’s own criteria via reports from at least two different agencies.

I can see two reasons for this choice. One, the Interpol list really is “the worst of the worst”, so there’s even less reason to oppose it — except, yes, it won’t work. Two, for various technical reasons explained by Glen Turner, filtering against the ACMA blacklist has a real potential for a real performance hit on internet use, whereas the Interpol list does not.

ISPs can also buy a magic box that filters against the Interpol list automatically and that the manufacturers say they can install in 10 minutes.

“The ACMA plays no role in the voluntary filtering scheme involving the Interpol list that some ISPs may be implementing,” said ACMA.