Apple has made a small change to a Mac marketing webpage that is a big deal to people who care about computer security.

We’re talking about the “Why you’ll love a Mac” webpage. For the past couple of years, Apple has claimed that the Mac “doesn’t get PC viruses,” adding that “a Mac isn’t susceptible to the thousands of viruses plaguing Windows-based computers.”

That’s a tough one to argue with. After all, Windows software doesn’t work on the Mac operating system. But now, it’s a claim that Apple doesn’t seem comfortable making anymore.

As antivirus seller Sophos has pointed out, Apple recently changed the page to include a wimpier statement about Mac OS X security. “It’s built to be safe,” says Apple. “Built-in defenses in OS X keep you safe from unknowingly downloading malicious software on your Mac.”

After a long run of dodging the kind of widespread worms and viruses that have run rampant in Microsoft land, this past year has been a bit uncomfortable for Apple, security-wise. First, there was MacDefender, the Trojan horse program that reportedly lit up Apple’s tech support lines a year ago. It was followed by a nasty little piece of work called Flashback, which was used by criminals to generate fake search engine and then drive unsuspecting users to websites they didn’t really want to visit