I had taped the password over their monitor, so my boy could use it. But this kid wasn't my son. He wasn't even one of my son's best friends. I had only seen him before once.

I realized I had to tighten up security -- change my password, and find a way for my kids to get on that didn't require purchasing separate accounts. It isn't easy.

So I hit the literature, and read two new books about office security. Friends, it's a jungle out there.

In E-Commerce Security: Weak Links, Best Defenses by Anup K. Ghosh (John Wiley, $24.99) Ghosh tells of the infamous German cracker group, Chaos Computer Club, who demonstrated on TV how an ActiveX control (a Microsoft version of Java) on their web site can be used to move money from the reader's bank account (via Quicken) to an account set up by the website. People lured by your website's title, "Becoming a millionaire in 5 minutes," don't realize till their bank statement arrives in the mail that the millionaire was them, not you.

In another scam, web surfers are told that they can download free pictures of naked people at a certain site. The only restriction is that they must first download "viewing software." But the software was a Trojan horse. As soon as it was executed, it disconnected from the user's Internet provider, turned down the modem volume, and dialed another provider, in the former Soviet republic of Moldova. The program then changed your Dial Up Networking configuration so that every time you logged on to the Internet, it was through your new Moldavian ISP. Monthly access charges for many victims topped $10,000. On the other hand, you did get the free pictures of naked people.

E-Commerce Security is loaded with horrific tales like this, and ways businesses and individuals can protect themselves against cybercons and e-grifters. The subtitle of the other book, Commercial Espionage, "79 ways competitors can get any business secrets" (Global Connection, $49.95), makes it sound like a handbook for snatching other folks' data. But it, too, is primarily a defensive guide. Executives of the Captain Queeg sort will love it, for it encourages you to conduct surveillance on employees, record them on video, and pore through trash bins looking for signs of suspiciousness -- if you can do these things without appearing mighty suspicious yourself.

An assumption is that surveillance is being conducted against you already in a kind of commercial equivalent of war, so countermeasures that might seem extreme in peacetime are not extreme now.

This is a dark world, in which innocent-seeming propositions are serpentine tricks, or preludes to litigation. A Korean visitor to an Italian pharmaceuticals company accidentally dropped a handkerchief into a fermentation vat. Back in Korea, the cloth was wrung out, and a valuable tuberculosis drug was extracted and reengineered.

Parad suggests these tactics to quash electronic surveillance: playing background music during important conversations; jamming listening devices by embedding aluminum strips in office windows. or installing windows with bulging contours; conducting routine bug sweeping operations wherever employees gather.

For all his distrust, however, Parad recommends fairly pedestrian computer security measures: tracer systems that can track computer break-ins, screensavers that require passwords to resume computing, antivirus programs to combat infected downloads, firewalls to keep proprietary information off the Internet, and facing monitors away from doorways so passersby can't read what's on 'em.

I mean, duh. And for $49.95.

In his defense, Parad's focus is less on computers and the net than on the more conventional, analog ways that business-critical information can find its way into your enemies' hands. If it were more computer-oriented, Parad (a lawyer who according to his website at http://www.denvica-mall.com, also consults on such matters as how to get traffic tickets dismissed and how to pass exams on any subject) might have to concede that information in the new age is virtually unprotectable, and quickly loses its value anyway.

Like the good people at Doritos might say about confidential data, Help yourself, we'll make more.

Which brings me back to my home-based security problems. I've already installed a firewall around my Quicken account, changed my Internet passwords, and taken the extraordinary measure of not taping them on the monitors.

So I'm ready. Come on over, "Rickie," if that is your real name. Just tell us what you are really after. And could you speak a little louder and into the plastic rose?

Hear Mike tell Irish techno tales on St. Patrick's night, Tuesday, March 17, 8 p.m. at Acadia Coffeehouse, at the corner of Nicollet and Franklin Avenues in Minneapolis.

America's Best-Loved Technology Writer(TM), Michael Finley has a free gift for visitors to http://mfinley.com.