Occasionally I spend a day wandering from trial to trial in the Downing Centre, Sydney's giant justice factory. It's one way of keeping in touch with certain aspects of the city. A while ago I began to notice small dark men in the dock, always with an interpreter.

These are the crew from the Indonesian boats that carry asylum seekers to our shores, charged with people smuggling and farmed out by the Commonwealth to the states for justice. There are lots of them: as of last September, almost 200 had been convicted and another 251 were due before the courts.

The trials generally follow the same pattern: a naval and a federal police officer are flown down from north Australia to give evidence, followed by half a dozen passengers from the boat, who are brought from some distant detention centre to confirm that the accused was in fact responsible for sailing the vessel. The evidence can be interesting when the passengers describe their journey from home in some detail.

If you attend one of these trials, which are open to anyone, you will notice a strange thing. Although our leaders have long assured us the crew of these boats are vile people smugglers preying on human misery, in fact they often seem to come from far more wretched circumstances than their passengers.

These are frequently well educated people such as engineers who, despite the problems that made them leave home, were wealthy enough to raise something like $10,000 for the passage of each member of their families. And most of them have a future in Australia. The fishermen, in contrast, are the poorest of the Indonesian poor - as their appearance indicates, they come from the fringes of the Javanese empire.

Often they were ignorant of what they were doing. At his trial a fortnight ago, Abdul Suares from Sulawesi described how he and three boys were placed on board SIEV 228 at the last stage of its journey, and watched in confusion as the main crew took off in another vessel. He said he had been offered $540 for a crewing job and had not been told he was going to Australia (the trial resulted in a hung jury).

They are generally illiterate and face almost certain incarceration for three years, far from their families, followed by a return to an impoverished village. It's true they won't face persecution on their return, but there are circumstances in life just as bad as the risk of being persecuted.

I am not trying to compare one person's misery with another's, just pointing out that, in human terms, the virulence with which Australia punishes these crew members, nearly all of whom are found guilty and receive a mandatory three years in jail, is very odd. It fulfils no conceivable policy objective. Jail sentences are supposed to punish, but this is excessive: other criminals receive less for offences involving considerable violence or sex crimes.

Deterrence is another objective of sentencing, and probably three years in jail will deter these men from crewing a boat to Australia again. But, again, the same effect could be achieved with a shorter sentence. As to deterring others from committing the same offence, word about sentences handed out in the Downing Centre does not seem to have reached Indonesia's outer islands, because the boats keep coming.

Apart from not being effective, the policy is also hugely inefficient. One source high in the justice system estimates each trial costs about $250,000, while the jail time served is another $219,000 per prisoner. The large number of trials - for which NSW has been given no extra resources by the Commonwealth - is clogging up our justice system, placing increasing pressure on the courts, the Legal Aid service, and the prisons.

A lot of this could be avoided if, as in almost all other criminal matters, a plea of guilty were rewarded with a discount off the sentence. But because of the mandatory sentence here, no discount is possible, so most of the accused chose to go to trial in the faint hope something might turn up.

If a government policy does not fulfil any admirable objective, and is grossly expensive, we usually look for a political explanation. But if this one was supposed to appeal to anti-boaters by being tough on people smugglers, it has woefully failed to find its main targets.

Last year in the District Court, Judge Brian Knox sentenced Asse Ambo for bringing SIEV 229 and its 53 passengers to Australian waters. His honour (as I reported at the time) went to the trouble in his judgment of describing the nine stages in the human supply chain that brought its 53 passengers from Tehran and Baghdad. They paid about half a million dollars in total for the journey. How much did Ambo receive? Two hundred and seventeen dollars.

This is typical of the government's almost complete lack of success in catching the people smugglers who really matter.

In the four years to last September, just five organisers had been convicted here. As for overseas, Canberra likes to boast about its efforts to work with other governments to catch the big boys, but this is unproductive: in the same period, one organiser had been convicted in Indonesia while three people had gone down in Malaysia for harbouring illegal immigrants.

If anyone believes locking up poor fishermen is effective or reflective of success in the government's more general efforts against people smugglers, it's time Alan Jones disabused them. Someone is playing a cruel trick on those citizens concerned about border security.

Unhappiness with what is happening is simmering in the judiciary. About 10 judges have spoken out against the system in courts around the country, mainly upset by the mandatory sentences they have to give, both the principle and the length.

Last year Judge Knox said in his judgment it was difficult to see how mandatory sentencing could be reconciled "with the duty imposed by the Crimes Act to deliver a sentence which is 'of a severity appropriate in all the circumstances of the offence'."

Tough Laws On People Smuggling Are A Con