Zero tolerance, on the part of the user community, is the only policy that can work.

It’s similar to the “broken windows” theory of urban decay, which holds that if a single window is left unrepaired in a building, in fairly short order, the remaining windows in the building will be broken. Fixing windows as soon as they are broken sends a message: that vandalism will not be tolerated. But not fixing windows also sends a message: that vandalism is acceptable. Worse, once a problem such as vandalism starts, if left unchecked, it flourishes.

My answer to question posed earlier — why are Windows users besieged with security exploits, while Mac users suffer none? — is that Windows is like a bad neighborhood, strewn with litter, mysterious odors, panhandlers, and untold dozens of petty annoyances. Many Windows users are simply resigned to the fact that their computers contain software that is not under their control. And if they’ll tolerate an annoying application that badgers them with pop-up ads, well, why not a spyware virus that logs every key you type, then sends them back to the creator? (That’s a real virus, by the way, Korgo, which hit Windows at the end of May and is spreading quickly.)

The Mac is like a good neighborhood, where the streets are clean and the crime rate low. You don’t need bars on your windows in a good neighborhood; you don’t need anti-virus software on the Mac.