If you're an employer, there are several things you should do. First, develop a formal, acceptable usage policy and make sure every employee knows about it. Tell them that their computer use may be monitored at any time, and provide clear guidelines for what constitutes acceptable use of company email servers and the Web.
Use monitoring software as an early warning system to identify potential problems. Scan management reports regularly, and if you see wide-scale problems, restate the company policy immediately. Provide at least one warning to employees who misuse resources, and give them a chance to correct their behaviour. You should also install blocking software to prevent employees from accessing sites you consider inappropriate -- a £1,000 software package can easily prevent a £1m sexual harassment lawsuit.
If you're an employee, you can protect yourself by reserving corporate email addresses for business correspondence. Avoid using your company email address to send personal messages. If you have a personal account with an ISP, use that address for all personal mail. Encourage all your personal correspondents to use your private address for non-business-related messages.
Also, report spam as soon as you get it. If you receive unsolicited commercial email, especially messages that contain graphic sexual content, forward them to your mail administrator immediately and request that they block the sender. Never forward jokes, cartoons, chain letters or other email debris from your company account. Email administrators take a dim view of bandwidth-clogging attachments, which often proliferate around holidays. Likewise, even a hint of sexual innuendo in a joke can trigger a harassment lawsuit. Hit the Delete key instead of the Forward button.
Finally, keep a close watch on your Web-browsing habits. If your employer allows you to surf the Web for personal business, make sure you use the privilege sparingly. Assume that every page you load will be saved on a corporate server.
Take me to the Surveillance 2 ZDNet News special.