This is my sixth column for Wired.com:

It’s a David and Goliath story of the tech blogs defeating a mega-corporation.

On Oct. 31, Mark Russinovich broke the story in his blog: Sony BMG Music Entertainment distributed a copy-protection scheme with music CDs that secretly installed a rootkit on computers. This software tool is run without your knowledge or consent — if it’s loaded on your computer with a CD, a hacker can gain and maintain access to your system and you wouldn’t know it.

The Sony code modifies Windows so you can’t tell it’s there, a process called “cloaking” in the hacker world. It acts as spyware, surreptitiously sending information about you to Sony. And it can’t be removed; trying to get rid of it damages Windows.

This story was picked up by other blogs (including mine), followed by the computer press. Finally, the mainstream media took it up.

The outcry was so great that on Nov. 11, Sony announced it was temporarily halting production of that copy-protection scheme. That still wasn’t enough — on Nov. 14 the company announced it was pulling copy-protected CDs from store shelves and offered to replace customers’ infected CDs for free.

But that’s not the real story here.

It’s a tale of extreme hubris. Sony rolled out this incredibly invasive copy-protection scheme without ever publicly discussing its details, confident that its profits were worth modifying its customers’ computers. When its actions were first discovered, Sony offered a “fix” that didn’t remove the rootkit, just the cloaking.

Sony claimed the rootkit didn’t phone home when it did. On Nov. 4, Thomas Hesse, Sony BMG’s president of global digital business, demonstrated the company’s disdain for its customers when he said, “Most people don’t even know what a rootkit is, so why should they care about it?” in an NPR interview. Even Sony’s apology only admits that its rootkit “includes a feature that may make a user’s computer susceptible to a virus written specifically to target the software.”

However, imperious corporate behavior is not the real story either.

This drama is also about incompetence. Sony’s latest rootkit-removal tool actually leaves a gaping vulnerability. And Sony’s rootkit — designed to stop copyright infringement — itself may have infringed on copyright. As amazing as it might seem, the code seems to include an open-source MP3 encoder in violation of that library’s license agreement. But even that is not the real story.

It’s an epic of class-action lawsuits in California and elsewhere, and the focus of criminal investigations. The rootkit has even been found on computers run by the Department of Defense, to the Department of Homeland Security’s displeasure. While Sony could be prosecuted under U.S. cybercrime law, no one thinks it will be. And lawsuits are never the whole story.

This saga is full of weird twists. Some pointed out how this sort of software would degrade the reliability of Windows. Someone created malicious code that used the rootkit to hide itself. A hacker used the rootkit to avoid the spyware of a popular game. And there were even calls for a worldwide Sony boycott . After all, if you can’t trust Sony not to infect your computer when you buy its music CDs, can you trust it to sell you an uninfected computer in the first place? That’s a good question, but — again — not the real story.

It’s yet another situation where Macintosh users can watch, amused (well, mostly) from the sidelines, wondering why anyone still uses Microsoft Windows. But certainly, even that is not the real story.

The story to pay attention to here is the collusion between big media companies who try to control what we do on our computers and computer-security companies who are supposed to be protecting us.

Initial estimates are that more than half a million computers worldwide are infected with this Sony rootkit. Those are amazing infection numbers, making this one of the most serious internet epidemics of all time — on a par with worms like Blaster, Slammer, Code Red and Nimda.

What do you think of your antivirus company, the one that didn’t notice Sony’s rootkit as it infected half a million computers? And this isn’t one of those lightning-fast internet worms; this one has been spreading since mid-2004. Because it spread through infected CDs, not through internet connections, they didn’t notice? This is exactly the kind of thing we’re paying those companies to detect — especially because the rootkit was phoning home.

But much worse than not detecting it before Russinovich’s discovery was the deafening silence that followed. When a new piece of malware is found, security companies fall over themselves to clean our computers and inoculate our networks. Not in this case.

McAfee didn’t add detection code until Nov. 9, and as of Nov. 15 it doesn’t remove the rootkit, only the cloaking device. The company admits on its web page that this is a lousy compromise. “McAfee detects, removes and prevents reinstallation of XCP.” That’s the cloaking code. “Please note that removal will not impair the copyright-protection mechanisms installed from the CD. There have been reports of system crashes possibly resulting from uninstalling XCP.” Thanks for the warning.

Symantec’s response to the rootkit has, to put it kindly, evolved. At first the company didn’t consider XCP malware at all. It wasn’t until Nov. 11 that Symantec posted a tool to remove the cloaking. As of Nov. 15, it is still wishy-washy about it, explaining that “this rootkit was designed to hide a legitimate application, but it can be used to hide other objects, including malicious software.”

The only thing that makes this rootkit legitimate is that a multinational corporation put it on your computer, not a criminal organization.

You might expect Microsoft to be the first company to condemn this rootkit. After all, XCP corrupts Windows’ internals in a pretty nasty way. It’s the sort of behavior that could easily lead to system crashes — crashes that customers would blame on Microsoft. But it wasn’t until Nov. 13, when public pressure was just too great to ignore, that Microsoft announced it would update its security tools to detect and remove the cloaking portion of the rootkit.

Perhaps the only security company that deserves praise is F-Secure, the first and the loudest critic of Sony’s actions. And Sysinternals, of course, which hosts Russinovich’s blog and brought this to light.

Bad security happens. It always has and it always will. And companies do stupid things; always have and always will. But the reason we buy security products from Symantec, McAfee and others is to protect us from bad security.

I truly believed that even in the biggest and most-corporate security company there are people with hackerish instincts, people who will do the right thing and blow the whistle. That all the big security companies, with over a year’s lead time, would fail to notice or do anything about this Sony rootkit demonstrates incompetence at best, and lousy ethics at worst.

Microsoft I can understand. The company is a fan of invasive copy protection — it’s being built into the next version of Windows. Microsoft is trying to work with media companies like Sony, hoping Windows becomes the media-distribution channel of choice. And Microsoft is known for watching out for its business interests at the expense of those of its customers.

What happens when the creators of malware collude with the very companies we hire to protect us from that malware?

We users lose, that’s what happens. A dangerous and damaging rootkit gets introduced into the wild, and half a million computers get infected before anyone does anything.

Who are the security companies really working for? It’s unlikely that this Sony rootkit is the only example of a media company using this technology. Which security company has engineers looking for the others who might be doing it? And what will they do if they find one? What will they do the next time some multinational company decides that owning your computers is a good idea?

These questions are the real story, and we all deserve answers.