Warren Buffett has said we should "beware of geeks bearing formulas." But last week, we were momentarily set on edge by the prospect of geeks planting confickers — tens of millions of them — in hard drives all over the world.

If you don't know what a conficker is, it's not a type of pine tree ("Look at all them confickers out yonder") and it's not an exclamation ("Get those conficking conifers out of my yard!"). The allusion to Greeks and Trojan horses is apt, however.

Conficker is the latest computer virus, which was supposed to explode on the world April 1. These types of things often are referred to as Trojans. They come into your computer innocently and hide until given instructions from some other computer to begin making mischief.

In this case, the mischief still might come, although experts say it likely won't be the global conflagration some have predicted.

That's how it usually is. The computer threats that get all the attention (see Y2K) turn out to be not so bad. You can argue all day about whether this is because the attention leads people to take precautions, but no one can know for sure. The ones you don't see coming, however, really get you.

Suppose, for instance, that a bunch of smart people a few years ago had issued a warning about investors filling their hard drives with derivatives based on pieces of subprime mortgages, and how these were being calculated by computer programs and sent through the Internet to other computers used by investors and financial institutions worldwide.

Richard Dooling of the International Herald Tribune recently described this as Wall Street geeks feeding $1 trillion into their computers, massaging it with algorithms and creating "$62 trillion in imaginary wealth."

"It's not much of a stretch," he continued, "to imagine that all of that imaginary wealth is locked up somewhere inside the computers, and that we humans ... are frantically beseeching the monolith for answers."

Perhaps, he said, "we have somehow managed to colossally outsmart ourselves using computers." Viruses don't always have to be the traditional kind, you know.

Earlier this year, I had to hire someone to come to my house and rid my computer of some bad viruses that took me to certain Web sites regardless of where I really wanted to go. They also kept throwing pop-ups onto the screen warning to me to buy things.

But those could be removed fairly easily with the right tools and few dollars. No one seems to know how to rid us of the toxic assets infecting the world's banks, and politicians seem to keep falling for the annoying pop-up ads asking for more money.