Is Big Brother watching you? If you are an employee with a connection to the Internet sitting on your desk, he may be. Companies are increasingly taking steps to ensure their workers do not abuse the privilege.

In the US, where access to the Internet is an integral part of many white-collar workers' jobs, some employers are already monitoring the use of the technology. They are mostly trying to guard against staff using the World Wide Web to examine pornography, or collect illegal material.

In Europe, most employers have so far turned a blind eye to the use of corporate Internet connections for private surfing. However, that is changing, as was shown in Britain last week when an industrial tribunal upheld the dismissal of a woman manager who searched the Internet at work for cheap holidays.

Ms Lois Franxhi was sacked by Cheshire-based Focus Management after logging on 150 times to Internet sites concerned with holidays. As the number of Internet-enabled companies rises - along with evidence of connections being misused - such cases are likely to recur.

A survey by Integralis, a network security specialist found that 15 per cent of directors at 800 large British companies said they had already disciplined at least one employee for inappropriate use of the Internet at work.

Many directors also believed email was being used to spread material that could expose their companies to legal action. In the US, there have been a number of cases of employers being sued after staff received sexually and racially abusive e-mail messages.

The Integralis survey found that directors believed each employee could be wasting up to two hours a day spending, receiving or reading personal e-mails, or on surfing the Internet.

Employers that take such a dim view of their own staff have a couple of alternatives. The first is to lay down a clear policy on Internet usage - something that is far more common in the US than in Europe. Such policies tend to cover the sort of e-mails that can be sent, and the company's view of what kinds of Internet surfing are acceptable.

A more radical step is to install a piece of software that monitors and reports on how employees are using the personal computers upon their desks. Such software tools can now distinguish in a sophisticated manner between harmless and undesirable Internet use. For example, they may allow a search for material on breast cancer, while blocking another from looking for a pornography site on breasts.

One such software tool is made by Elron, a US company. This can monitor how corporate Internet connections are being used, and either block access to particular sites, or flash alerts to managers. The software can also be set up to deliver a league table of employees, based on how often they have downloaded sexual or violent material. It is estimated that a quarter of companies in the US have now installed systems to track their employees' surfing activity. There is also growing pressure, especially within the US, to install monitoring software in schools, colleges and public libraries.

The US Congress signalled its intention last week to pass legislation which would require schools and libraries to install filtering software. One of the driving forces behind the move has been the string of school gun tragedies including the Littleton, Colorado attack which left 15 dead. The Littleton killers were heavy users of the Internet.

But while intensive monitoring of young people's Internet use may be necessary, should the same approach be tried in the workplace? The large volume of resources now available on the Internet could equally be treated as an opportunity for staff and employers. There are strong arguments that companies benefit from having a workforce that is familiar with the breadth of the Internet. As they try to develop their electronic commerce and Internet activities, even personal Internet use could be regarded as a form of employee training.

The use of employee guidelines is likely to be the method chosen by many employers to combat misuse, without restricting legitimate use of an Internet connection at work. But as Internet portals develop a range of services that include both business and personal applications, it could become ever harder to draw the line. If Big Brother is watching, he will have to do so closely.