Microsoft is getting into the security game. Some folks say, "It's about time." Others say, "Haven't they had security for years?" I look it at it quite differently.

The facts: Microsoft acquired the anti-virus company GeCAD in 2003 and recently acquired anti-spyware maker Giant Company Software . Microsoft obviously plans to compete with Symantec, Network Associates and other companies that have made billions of dollars protecting users from the security holes in Microsoft products.

Now what's wrong with this picture? I firmly believe in homogenized milk, but not a homogenized network or computer system.

Imagine this scenario. MicroHome, a do-it-yourself construction company, builds a nice, simple shell for a house that lets people build effective, usable homes for themselves. MicroHome becomes enormously successful. Then other companies begin to offer materials such as tile roofs, better carpeting, lead-free paints, aluminum exteriors, upgraded appliances and so on. MicroHome wants a piece of that action, too, so it adds various enhancements to each new version of its products.

One day, NovaHome, a Utah company, notices that the only way to get from one MicroHome to the next is to fill a little floppy basket with goodies, put on a pair of sneakers and march down a winding path through the woods until you get to the next MicroHome. So NovaHome builds Inter-Home Express (IHX), a high-speed road system that lets every MicroHome attach an on-ramp/off-ramp. Now all the people can visit each other's homes easily.

However, some bad kids in one neighborhood notice that MicroHome didn't build locks into the doors and windows of its off-the-shelf houses. As a result, they can leap onto NovaHome's IHX and get into anyone's house they want.

Companies start to provide locks and keys for the MicroHomes. Eventually, MicroHome gets the hint and decides to add locks and keys to the houses it sells. However, MicroHome builds the lock-and-key systems in such a way that if a kid breaks into one MicroHome, he and his friends can break into any MicroHome.

Here's another scenario. Imagine you own a large, multinational company. Every door, window, desk, filing cabinet, garage and delivery truck in your facilities has a lock and key. Would you, as a responsible corporate leader, use the same locks, made by the same company, using the same keying system, for everything of value in your company?