Books hed: Notes from the underground dek: the information in 'Steal This Computer Book 2' could be useful-in the right hands.

Few computer books stir up emotions. Fewer still are published with a stern, back-cover blurb that resembles a Surgeon General's admonition: "Warning: This book is not to be used for hacking into government computers, shutting down AOL, cracking software, phone phreaking, spreading viruses, or any other illegal activity."

Yet troubling thoughts quickly can surface while reading "Steal This Computer Book 2" by Wallace Wang (No Starch Press, $24.95, paperback), a stand-up comic and best-selling computer writer who has penned many "Dummies" books. It can be tough to decide whether to praise or condemn it.

To begin with, this revised second edition of Wang's controversial big-seller is packed with how-to tips on everything from surreptitiously capturing computer keystrokes to stealing passwords, writing viruses and getting undeserved student discounts on software.

It also describes how to send anonymous e-mail and create havoc online with programs that generate fake credit-card numbers.

At the same time, these troubling details are offset with positive instructions such as how to recover from computer viruses, protect data with encryption programs, and fight back against spammers who overload your e-mail.

In short, there is something for everyone--on both sides of the law.

The author believes that while knowledge is power, information itself is "neutral." He concedes, however, that if you know how bad things can be done to you via the Internet or by digital troublemakers within your office, you may (a) take protective measures or (b) become a digital troublemaker yourself.

"This book won't turn you into a hacker any more than reading a military manual can turn you into a soldier," Wang argues. Yet it might, depending on your nature and mindset.

Wang invites readers into "the underground of the real computer revolution, where everyone is encouraged to question, explore and criticize, but most importantly, to learn how to think for themselves."

His book starts innocently enough with a treatise on how to use search engines. Soon, though, the topics range from how to defeat parental-control software to how to monitor hate groups online, how to hook up with hacker groups, and how to write viruses.

To be fair, several chapters are devoted specifically to ways to protect your computer and software from intrusion and damage. And what you learn about the sneaky techniques of troublemakers can help you learn to be more cautious and alert. It can be fascinating to read such details as to how computers can be attacked and how easily software protection schemes can be cracked with the help of Web sites. It also can be upsetting to almost any sense of honesty and fair play.

Some computer users will love this book and accompanying CD. Others will hate and fear the package, especially for what it reveals in a matter-of-fact and often entertaining fashion.

Bottom line: "Steal This Book 2" is out there. What you choose to do about it is strictly up to you--and your human nature.