Think that most of your Internet activity - browsing, shopping, posting messages, sending e-mail - is private? Think again.
Give your PC a privacy test: Any time you're connected to the Net, your PC is open to the world. Gibson Research's ShieldsUp site (http://grc.com) features the Test My Shields and Probe My Ports links that establish a secure connection and show you a Web page with the information that a hacker could find out about your computer and LAN. You will likely see your name, your IP address, and the number of "ports" on your computer that could allow anyone who has the right software to scope out your hard disk and its contents.
Don't share your files: hackers can gain access to your computer when your PC is set to share files and printers. Even if you aren't on a network, your PC's settings may be configured to allow file sharing - and hacker entry. To turn off access to file and printer sharing in Windows 9x, select Start-Control Panel, double-click the Networks icon, and select the Configuration tab. Click the File and Printer Sharing button, and make sure that both boxes in the dialogue box are unchecked.
Study the trail you've left: the simplest way to block intruders from your PC is to install a firewall. But firewalls only defend PC ports that allow file sharing; they don't hide your browsing habits. To see what information you're giving away, check Privacy.net's Anonymizer analysis page (www.anonymizer.com), which lists the sites you've visited and any cookie-related information they deposited on your PC. For real anonymity, you need an anonymous browsing service that cloaks your identity - or lets you establish an alias that nobody can trace back to you - and routes all your activity through its own anonymous servers.
Surf anonymously for free: Anonymizer is the most venerable free anonymity service. Enter any Web address at www.anonymizer.com, and the site will take you there but conceal your IP address and other identification.
Privada's PrivadaProxy and Zero-Knowledge Systems' Free-dom 1 provide anonymity online via software/Web site combos and add other benefits.
PrivadaProxy's Web Incognito service lets you set up an alias to use online and interposes a proxy server between you and any site you visit. You can set up as many online identities as you like for a monthly fee of $US5 each. The software allows you to configure settings for cookies and e-mail filtering, but your browser must be set to run through a proxy server. In Internet Explorer, select Tools-Internet Options-Connections-LAN Settings. In Netscape, select Edit-Preferences-Advanced-Proxies, double-click Advanced, and select "Proxies.
Freedom 1 uses a network of anonymising servers and strong en- cryption on your PC to confound any site that tries to trace your connection back to your PC. Online aliases, known as nyms, supply a browsing identity and an encrypted e-mail account (firstname.lastname@example.org). Five nyms with a one-year life span cost $US50. Instructions are routed through one, two, or three intermediate servers, slowing browsing but simplifying mail cryptography and spam control.