"We think more people ought to buy them," Thompson said of Apple's Macintosh computers, in response to a question from the audience at the Future in Review conference on Monday.
The "target-rich" environment created by Windows vulnerabilities means that virus writers and hackers have set their sights on Windows PCs, he said.
However, Thompson noted that if more and more people did go out and buy Macs, virus writers might change their tactics. And many attacks are increasingly of the phishing or identity theft variety, which targets computer users independently of their operating system, he said.
"We shouldn't assume that any one technology at any layer is sufficient to protect our notion of a connected world," Thompson said. Computer users and network operators need to take many steps to ensure their data will be protected, regardless of which products they use, he said.
Security problems haven't gotten as much attention from the US government as Thompson had hoped, although things have improved compared with four years ago, he said. Still, computer "security has fallen off the (government's) radar screen with budget issues and the war in Iraq," he said.
However, Microsoft's move into the security software market has clearly gotten Thompson's attention. "We are concerned (whether) they will play fairly. If they do something that is unfair, then that will be something that is difficult to compete against, but we'll have other venues for making our point," he said.
