When is a CD not a CD? According to Philips, inventor of the music CD format, it is only a "CD" when it has their CD logo on it.
Now before you think I'm being pedantic, let me tell you why this is important: if you go into a High Street music store and pick up a "CD" produced by Sony, you are likely to be buying a " silver disk" with music on it and not a genuine CD.
In an attempt to foil the music pirates Sony's " silver disks" are loaded with a virus-like software that infects your PC the minute you slide the tray back into the drive.
Known as XCP, this software uses a virus writers' trick known as a rootkit to flip the lid of your Window operating system and mess with its mind, thereby preventing you from copying the CD (whoops, I mean "silver disk") or indeed listening to it on your PC with anything other than the supplied music player.
Admittedly it will work if you put the disk into a HiFi music player, which will be fooled into thinking it is an actual CD and play it like any other.
This XCP stealth software has only just been discovered. Its rootkit prevents it from being detected by your average virus scanner and there is no easy way to uninstall it.
Sony is under fire for this tactic, but their lawyers keep referring everyone back to the small print they put on the disk sleeve - you know, the words you need a magnifying glass to read, which inform the buyer that XCP will be installed should the disk be used on a computer.
Now if they put the words "Warning: this is not a CD" in big letters across their disks I'm might have some sympathy, as long they followed them with the words "Oh, and we're gonna screw with your PC the minute you insert it".
Or how about popping up a box on your computer when the disk is inserted saying "We're about to install some secret files on your PC so we can keep an eye on you - is that OK?"
Mac and Linux users are unaffected by this, and indeed the whole malware problem that blights the Windows world.
But don't get too smug you Apple fans. Once Apple moves to the Intel chipset for the Mac they've said they're going to start using trusted computing features in the hardware that will allow them to exert similar levels of control within Mac OS.
More consumer-friendly voices at Sony have said they intend to stop using the XCP system soon and it was only one of many experiments they were conducting to find the perfect solution to their problem.
So heaven knows what else they have been up to using their paying customers and their PCs as unwitting guinea pigs.
* Chris is managing director of Interernet consultancy WebXpress. This and other unedited articles can be found at webxpress. com/ email firstname.lastname@example.org