People have been trying to cheat and otherwise victimize one another since, no doubt, we learned to walk upright. On the other hand, some people subordinate all or almost all personal goals to help their fellow man and woman. The vast majority of us-regular Joes and Janes who are trying to get ahead, playing by the rules, and avoiding problems-occupy the space between these extremes.

The internet gives us tools for getting ahead, but it also gives the bad guys tools for getting us. Instant messaging and texting may be more popular with the kids, but email remains the most common way we communicate digitally. Using email is also an easy way to become victimized. Avoiding victimization requires a little knowledge of the common scams-new ones are popping up all the time-and a little common sense.

A lot of advice about internet risks complicates the issue, and too much advice can scare you away completely, which is a needless overreaction. Still, you need to protect yourself; and even if you think you're protected, it never hurts to double-check.

• Be wary of offers of help. These are among the oldest email threats, originating in the early 1990s from Nigeria. If you help Mrs. Magdalene, a recent widow, by paying an export fee with American currency, she would be more than happy to help you, sharing part of a large inheritance that she wants to invest safely in the U.S. Sometimes called advanced fee fraud, these scams always involve attempts to persuade you to pay a relatively small fee in order to realize a much larger gain.

• Ignore threats. Crooks sometimes take a tough-guy approach rather than a helpful one, to try to scare you into supplying your personal credit card, banking, or other information to avoid collection agency involvement and other hassles. If in doubt, find the phone number yourself and call.

• Be cautious about links. Sophisticated-looking email can trick you into clicking on a link to take you to the website of what you think is an online payment service, government agency, or other entity you may have a relationship with. These phishing attacks are a bona fide epidemic. If in doubt, type the web address in your browser yourself or use your own bookmarks or favorites link.

• Double-check attachments. This is another old ploy, and a common way in which viruses, worms, and other malware are spread. Even if the attachment comes from someone you know, it's good policy to check with that person to make sure he or she actually sent it. The bad guys are sometimes able to gain access to the email address books of people, pretending to be them.

• Don't respond to unsolicited ads. Spam emails often attempt to cheat you with offers of bogus health remedies and other scams. Legitimate companies don't operate by stealing your internet connection time and hard disk space.

• Use security software. A surprising percentage of internet users still don't do this, indicating that they haven't gotten the message. According to Consumer Reports' latest survey, 19% of users don't use antivirus software and 36% don't use an anti-spyware program. Of those users with cable or DSL connections, the most vulnerable, 5% don't use a software or hardware firewall to help prevent their computers from being commandeered.

• Keep current with operating system patches. If you use a Windows PC, it's almost always good policy to direct Windows Update to automatically download and install the latest security and other patches. And if you use a Mac, do the same with Software Update.

There's no good reason for this. Many subscriptions with internet services providers (ISPs), such as Comcast (www.comcast.com), come with free security software, in this case McAfee Security Center. You simply have to enable it.

If you don't have access to free software through your ISP, there are some very good free programs out there. AVG (http://free.avg.com) is a popular and highly regarded antivirus program available in both free and pay versions, with the free version providing excellent basic protection. Just make sure you don't use more than one antivirus program at a time; this can cause conflicts on your computer.

An anti-spyware program is also a must to keep performance-sapping snoops at bay. Spybot Search & Destroy (www.safer-networking.org) is an excellent choice.

Also, make sure you at least enable the software firewall that comes with Windows or the Macintosh operating system. Or you can download a free firewall; ZoneAlarm (www.zonealarm.com) is free for individual users.