For Robert McClelland, the Benbrika case represents Australia’s “most successful terror prosecution”.

But that very much depends on what you mean.

Most media reports imply that the conviction of seven men in Melbourne means that the police prevented terror attacks against targets ranging from the Westgate Bridge to the Grand Final.

But that’s not what the court found at all.

After all, it’s an offence under common law to attempt a crime, and has been for hundreds of years. These men were not charged with attempting bombings or murders. They were convicted under John Howard’s anti-terrorist laws.

Mick Keelty explains:

The problem with the legislation was that the legislation at the time talked about “the” terrorist act. And in the Benbrika matter there was no definite decision about “the” terrorist act but, in our view, clearly they were planning for “a” terrorist act. So we explained that to the previous government and that was when they recalled the Senate and changed the wording of the Act to “a”  terrorist act.

That seemingly trivial amendment (from “the” to “a”) meant that the prosecution didn’t need to prove any involvement in a specific act of terror. Benbrika, for instance, was found guilty of being a member of a terrorist organisation, directing the activities of a terrorist organisation and possessing a thing in connection with preparation for a terrorist act.

You might conclude that Benbrika and his friends had joined al Qaeda or a similar group, an organisation with defined aims and members. In fact, the terrorist organisation was simply the men themselves. As for the “things” that Benbrika possessed, they weren’t bombs or guns but videos and documents about overseas groups or about terrorism in general.

That was what the case involved. The men talked about terrorism. They read books about it; they looked at terrorist snuff videos; they discussed the theological ramifications of martyrdom. But they didn’t actually do anything themselves.

Insofar as specific targets were raised in the trial, most of them came from Izzydeen Atik, the defendant who pleaded guilty. It was Atik who claimed Benbrika wanted to attack the MCG and Crown Casino. But Atik was mentally ill and believed he could talk to birds, and the judge specifically warned the jury that Atik was a conman, liar and a fraud.

On the police recordings, Benbrika and his friends say lots of nasty things. They discuss martyrdom and revenge killings, and Benbrika says he wants to damage lives and damage property. But it’s all incredibly amorphous. The Herald Sun’s headline about “West Gate Bridge bomb plot”, for instance, rests upon a recording of Fadl Sayadi explaining that it might be possible to destroy the bridge if you snorkeled underneath and planted what he described as “thingos” underneath.

Sayadi didn’t have any “thingos” and neither did any of the other men. The only explosives referred to in the trial belonged to an undercover police officer codenamed SIO39, who invited Benbrika to come with him into the bush to detonate bombs.

As Keelty says, McClelland’s successful prosecution depended on the new logic embodied in the anti-terrorism legislation, a logic that substantially eroding the traditional insistence that a crime depended on both a guilty intention and a guilty act.

Think about it in a different context. Imagine a group of junkies who decide they’d like to sell drugs rather than buy them. They read internet sites about making speed and they talk about the merits of bringing smack in by ship and by plane. If a wiretap picks up their mutterings about commercial quantities of heroin, should the law treat them as if they were already Mr Bigs?

If drug dealing seems less serious than terrorism, try a different example. In a high school, a group of bullied misfits listen to grindcore, read books about serial killers and talk to each other about shooting their schoolyard tormenters. Say a teacher overhears them. The kids’ profile seems similar to that of Eric Harris and Dylan Klebold. So should they be treated as if they’d already conducted a Columbine massacre?

School and workplace massacres are just as horrible as terrorist attacks (and probably far more likely). But we’d never apply the logic of the anti-terror laws in those settings.

It might be hard to muster much sympathy for Benbrika. But if we allow men to spend decades in gaol for acts that they might have committed in the future, we’re establishing a very scary precedent.