A spate of sacked-for-surfing cases, where employees have been dismissed for overzealous Web surfing, for email harassment, or for visiting "inappropriate" Web sites, have raised public awareness about how and why employers watch their staff online. In fact, those angry emails you sent to your most annoying colleague, or the wasted afternoons you've spent surfing the Web instead of working, may have been seen by your boss. For network administrators, monitoring the data traffic on a network, and from it over a gateway to the Internet, has always been an important part of the job. Network security consultant with UK computer security firm Oceanus, Ian Johnston-Bryden, says there are various network tools available for administrators to keep a close eye on events in the cyber office. "The Compartmented Node Workstation (CDW) is basically a foolproof UNIX tool for watching everything on a network," says Johnston-Bryden. "There are also Linux tools such as Hunt and a number of in-built applications with NT for monitoring package traffic." There is also an increasing variety of commercial software aimed at helping employers monitor and control the activities of their employees across a network and over the Internet. Another UK computer surveillance company, Content Technologies, provides two such tools: Websweeper and Mailsweeper, which allow even the most amateur or part-time network administrator to follow people's Web browsing and email communications with considerable ease. Websense is another application that not only monitors what sort of sites a user is visiting but also allows certain "categories" of sites to be automatically restricted. Once installed on a network Websense will download daily updated lists of different kinds of sites that have been automatically searched and categorised as potentially inappropriate or even illegal. When first launched, this sort of filtering software was notoriously fallible: blocking obvious sex sites but at the same time allowing access to a wide range of blatantly unsuitable content. Wendy Hoey, product manager with Content Technologies, says the sophistication of these programs has improved. "It has a much higher threshold and I've seen demonstrations of how pages are categorised now. They are getting pretty close to a lexical analysis of each individual Web page, sorting out subtle differences in meaning," she says. But snooping on employees is not as simple as pressing a button. Abner Germanov, network analyst with the Internet security division of research firm IDC, explains: "There are of course different levels of security that employers will want to implement," he says. "Some employees for example may need wider access to the Internet than others and restrictions on Internet access might not need to be applied after someone has finished work." Matt Rotenberg, executive director of independent think tank Privacy International, says people who do not want their email read need to learn a few basic rules. "Using a Web-based mail service gets around email monitoring as does using encrypting email software. Anonymous Web surfing is also something that is getting more and more popular because it is one of the few ways people have to preserve their online privacy." Anonymous Web surfing, through such sites as Anonymiser.com or the browser Freedom, strips a user's Internet Protocol address so that he or she can't be electronically identified. Take me to Surveillance. What do you think? Tell the Mailroom.