Jack Bauer, Kiefer Sutherland’s character in the TV series 24, has been battling it for most of the current series.

The former Home Secretary, David Blunkett, warned that it could cripple the 2012 Olympics.

And US President Barack Obama is sufficiently concerned about it to order a root and branch review of computer security.

The issue, of course, is cyber terrorism. Some say it’s a potential threat not just to governments but also to the entire western economic system and infrastructure. Others say that if it were going to happen, it would have occurred already.

But in fact, it has. Last month, the Wall Street Journal (http://online.wsj.com ) reported that overseas hackers — probably from Russia and China — had penetrated the American power grid and left behind malicious software that could be triggered to shut down parts of the network in the event of conflict.

Estonia, Chechnya and Kyrgyzstan have all come under cyber attack (see http://tinyurl.com/ b2bgdf). In each case, the finger of blame was pointed at Russia.

In 2000, a disgruntled employee rigged a computerised control system at a water treatment plant in Australia and released 200,000 gallons of sewage into parks, rivers and the grounds of a major hotel.

Hackers have already gained access to the American air traffic control system — in fact, they caused a partial shutdown of the system in Alaska.

And the Office of the Inspector General (www.oig.dot.gov ) has warned that further modernisation of air traffic control, using internet protocol technologies, will create more opportunities for those intent on mischief.

In a security audit, it identified no fewer than 763 potential vulnerabilities that would allow an intruder to execute remote commands or introduce malicious software.

Meanwhile, the North American Electric Reliability Corporation (www.nerc.com ), which is responsible for the power grid, has admitted that more needs to be done to protect it.

A US Air Force General, Kevin Chilton, told reporters recently that he was frustrated with antiquated security measures at some military bases, where, instead of the latest security patches being installed automatically, users had to download updates for each PC.

Industry experts have gone a step further, describing America’s cyber-security as “embarrassing” — see http://news.bbc.co.uk/1 /hi/technology/8023793.stm .

The problem for most states is that crucial parts of their infrastructure are owned by private companies, meaning that every network needs to be secure, not just the government’s.

As a result, private companies have a key role to play.

The problem, in some cases, is that the companies in question don’t have the expertise to establish how their systems would perform if faced with a sustained attack.

But there’s another reason for private companies to be concerned about cyber terrorism. The Hackers Panel, a hitherto anonymous group, broke cover at this year’s Infosec conference (www.infosec.co.uk) to warn that those attacking a country might go after economic targets rather than its government departments.

They named some of the UK’s biggest companies, including Tesco (www.tesco.com ) as potentially attractive to attackers, because of their importance to the economy.

The jury is still out on whether cyber terrorism will be a major threat in the short to medium term. But in the meantime it does no company or organisation any harm to beef up its network security.

Even the great Jack Bauer in the current series of 24 wasn’t able to stop terrorists from infiltrating air traffic control and putting two planes on collision course.

What’s science fiction today often becomes science fact tomorrow.

Rob McConnell is regional director for SQS NI. (www.sqs-uk.com ). His e-mail address is rob.mcconnell@sqs-uk.com