It's scary: this 21st Century threat has grown even larger than all spam, viruses, and hacker attacks combined. Even the word "spyware" is insufficient to describe the breadth of nastiness inflicted by these malicious little rogue programs. AdGoblin, DLSearchBar, KaZaa, Gator... thousands of these little programs covertly install themselves on computers everywhere. Once installed, these "malware" programs will do various nasty things, including: reading your keystrokes, hijacking your browser, covertly reporting your email address to servers, serving up porn, and causing you pop-up window grief. Yes, you should be very concerned. Read this explanation of spyware/malware, and the five steps needed to destroy this viral menace.   (photo by Getty Images)