Macworld this month tells me that I should be "protecting my Macintosh" with a virus checker - not because there are any viable Macintosh viruses around, but because I am otherwise potentially passing on PC viruses to other PC users.

In response, although I don't doubt they are right, I have this to say:

Active virus software, which scans i/o for your computer, does so by inserting itself in the hardware/driver space and slowing ALL red/write operations by scanning.  This can cut the speed of a computer by up to 50%. Why in the world would I do that?

I scan my computer with the excellent (and free) CLAMvx (a Mac version of the PC program) in order to ensure I have not done anything that will impact my fellow users. This is adequate given the potentional risk and does not denegrate the I/O of my machine. Secondly, it does not pay into the money machine that is the virus industry. I call it an industry because I am positive (my paranoia may be showing) that there are funded virus factories, building new viruses to drive the virus industry (and subsequently continue the need for the AV manufacturers.

If they really wanted to stop viruses, they would include it in server hardware and network hardware, where the analysis could be done without the overhead of software processing - perhaps using an onboard processor for the virus checker, with the code in flash memory allowing easy updating. This could help eliminate the problem at distribution points rather than at the individual computer.

But that would kill the market for AV at the much larger consumer endpoint and lord knows, we wouldn't want to do that. :)