The World Trade Organisation meeting in Seattle last year drew more global publicity for the anti-capitalist demonstrations than the conference itself. A total of 500 people were arrested and the bill for damage was more than $2.5m (£1.7m).

It was the same story with subsequent WTO meetings in Washington (1,300 arrested), and earlier this month in Melbourne, when the World Economic Forum met, 50 protesters were taken to hospital.

Similarly, in June 1998, images of smashed windows in the City of London and scenes of vandalism in Parliament Square were flashed around the world. Wherever the "global establishment" meets to discuss global trade or economic policy, it is likely there will be a mass protest or violence.

This week, the International Monetary Fund (IMF) and the World Bank Group are holding their annual meetings in Prague. At least 15,000 demonstrators are expected to turn up. Some even arrived earlier this month for "training days" promoted on the internet.

The protesters' main interests are what they believe are the inequities of the capitalist system, the march towards consolidation and debt in the developing world. They are promoting today as a "Global Day of Action". The authorities have requested that they camp and police have asked them to meet in the Strahov football and athletics stadium, although it seems highly unlikely that those planning trouble will take up the invitation.

The demonstrators rely heavily on the internet to organise their protests. Huge numbers of papers have been circulated in advance by a disparate federation of protesters. Vast numbers of people know the demonstrators' plans, but few are aware of the agents provocateurs in their midst.

Two local factors are likely to exacerbate the situation in Prague. First, the boom in the tourist trade has attracted criminals - some well-organised - to the city. As well as these, there are more sinister groups with political crimes in mind.

The second factor is the local police. Few have received high-level training in the handling of mass demonstrations, so their approach can be hard line. They are also short of manpower and other resources. Under such pressures, the police have been known to turn their force on bystanders. Last year, a Swiss journalist covering a protest claimed that police beat and detained him for several hours.

In Prague, 5,000 soldiers have been drafted in to support the 11,000 police on duty. Woe betide any sightseer who gets mixed up in the wrong crowd.

Apart from the obvious threat to physical security, there are dangers lurking in the huge media presence at the talks. Banks and multinational retailers have been singled out for their behaviour in emerging countries, as have companies and groups involved in research into genetically modified foods, such as Monsanto.

It is, of course, very easy to denounce a company or organisation on the internet or by syndicated media reports carrying damning, untrue or exaggerated accusations. Masked protesters are well aware that good pictures make front-page news.

Any company or organisation planning to send delegates to the talks should be prepared to safeguard their physical security due to the threat of violent attack.

So what should companies and other organisations do to protect their people? The first task is to assemble as much information as possible about the event. There must be a full appraisal of any risk or threat and every possible contingency should be covered.

It is not usually necessary to stop a delegate attending but if there is a serious threat to their physical safety, a system of continuous assessment during the event will offer some support. Efficient communications and a well-rehearsed crisis plan are essential.

As well as protecting the physical security of delegates, the company's reputation must also be defended.

This can be done by setting up a conventional or internet-based rebuttal service in advance of the event. The key to defending both security and reputation is thorough research, planning and practical implementation.

Many companies still think that because a delegate is very senior, he or she can cope with any incident or adverse publicity without support. The company will know its key issues and managers should develop a system to safeguard the company's reputation.

Analysing potential scenarios, having statements prepared in advance and making sure they are effective can be difficult but all this has to be in place. If it does, the company should not be seen to hide, be defensive or arrogant.

The company should be seen to protect its employees and to respect others' views while defending its policies.

Maintaining balance and the moral high ground is always difficult but, with the right help, it can be achieved.

David Little is a director of Sheldon Little Associates, an international security and crisis management consultancy. Neil Huband is a consultant in reputation defence and corporate counsel to Sheldon Little Associates www.sheldonlittle.com