Is the war on terror worth it?

A US National Guardsman at LA International Airport.

Would you allow authorities to install and monitor closed circuit TV cameras in your house, if it helped prevent terrorism?

Would you grant police powers to knock your front door down and randomly search your home at any time for no apparent reason?

To detain you without trial for prolonged periods?

If not, how far would you be prepared to go?

What rights would you sacrifice to combat the pernicious evil of modern-day terrorism?

Impositions that sound unduly alarmist in 2005 may not seem so absurd a generation or two from now as imperilled western societies erode personal freedoms in order to ramp up national security.

Every new counter-terrorism measure infringes on privacy to some extent, and a welter of strategies are on the table in the wake of the second London bombing attacks.

Shoot-to-kill policies, national identity cards, random bag searches on public transport, beefed-up CCTV monitoring, bans on books and clerics who preach extremist ideas, electronic "strip" cameras - all are being touted as weapons in a war that looks set to last for a very long time.

Italy has just decided to jail or fine anyone caught covering their face in a public place, such as by wearing Islamic burqas, and to allow police to extract DNA samples without a suspect's consent.

British police, who mistakenly killed an innocent Brazilian electrician, are not even required towarn suspects they may be aboutto be shot, it has since emerged.

New York Mayor Michael Bloomberg recently had to apologise profusely to five innocent British Sikhs who were frog-marched off a sightseeing bus and forced to kneel on a pavement with their hands behind their heads after a transport worker became suspicious about them.

The Queensland and New South Wales governments have both supported New York's random bag searches on public transport, with former NSW premier Bob Carr arguing: "Your civil liberty not to have your bag searched is outweighed by my right not to be blown up."

Sydney airport is monitoring British and US trials of a machine that lets security staff see an image of passengers naked.

It is designed to reveal bombs, knives and guns, and has helped British police detect illegal immigrants in canvas-covered lorries.

But opponents say images, particularly those of children, could be misused.

Civil libertarians label many of the new proposals draconian, and are alarmed at the spectre of Big Brother-style mass surveillance.

But much has changed in the 20 years since former Prime Minister Bob Hawke was forced to dump his reviled Australia Card, and many people believe Australians are more prepared now to subjugate their individual rights to give governments more power to combat extremism.

Peter Solomon, a former Liberal who heads a company pioneering smart-chip technology in passports, said: "The only ones who might fear a national ID scheme are those who have something to hide. The civil liberty argument is a lot of hype."

Former NSW police commissioner Peter Ryan, now in charge of Olympic Games security, warned: "We in the west play the anti-terrorist game with kid gloves.

"The enemy, the terrorist, has no rules. And yet we pussyfoot around complaining that people's civil liberties are being infringed if they're held too long in custody or they're not treated properly."

Big Australian cities already have thousands of closed circuit TV cameras - at shopping centres, railway stations, courts, government buildings, ATMs, car parks and private buildings.

Former federal Labor attorney-general Michael Lavarch, now Queensland University of Technology law dean, warns: "If you go down the path of very extensive filming, there needs to be appropriate checks and balances.

"People have relatively few rights to stop themselves from being filmed and photographed."

Federal Privacy Commissioner Karen Curtis says: "We need to make sure we get the balance right between a person's individual rights and the competing interests of a collective society."

Queensland Council of Civil Liberties president Michael Cope said a national ID card database would create a huge target for computer hackers.

"It makes it easier by accumulating all the data in one place, and if you're sufficiently technologically sophisticated you break in from a computer system and you can pinch anybody's ID," Mr Cope said.

Federal government backbencher Steven Ciobo warned: "I would suggest it's only a short step before successive governments may require all Australians to have on them at all times their national ID card."

Mr Ciobo, however, has backed moves to annul citizenship and deport immigrant Australians who incite or support violence.

Sydney-based Muslim Sheikh Taj Aldin Alhilali also called for the deportation of any clerics preaching anti-western hatred.

Anti-vilification laws, however, can also inhibit free speech among those who might not have been intended targets.

Two Christian ministers are facing the possibility of jail terms in Victoria for preaching against Islam.

President Abraham Lincoln faced similar thorny issues in 1863, speculating that he could have prevented America's Civil War if he had arrested southern generals and sympathisers before they committed any offences.

Lincoln said he could see the time coming when he would be blamed for making too few arrests rather than too many.

As federal Attorney-General Philip Ruddock observed: "One hundred and forty years on, the debate has little changed."

- AAP