The ownership of your data

Another thought experiment: suppose your word processor and spreadsheet programs stored all of your files in encrypted form. But not encrypted with a key you choose, or know; instead, encrypted with a secret key of the manufacturer, who assures you that the encryption key will always be available to you. At least, as long as you remain a customer of theirs. Would you trust your business' important documents to that software?

Well, that hypothetical is a pretty fair description of what Microsoft is attempting to achieve. First, by using proprietary document formats that only their software can read. ("Buy our software, or kiss your old documents goodbye.") Second, by adding features that restrict access to a document. Now, you might like the idea that you can control who reads your documents. And if were under your exclusive control, that might be a useful feature. But this feature can also be used against you. Microsoft is already exploring a "rental model" for software, requiring you to pay a small monthly fee instead of buying the software outright. Guess what happens if you forget to pay?

Or if Microsoft's validation servers screw up?

Or if the vendor goes out of business? (or just retracts service?)

It's not just Microsoft, by the way: this risk is inherent in all of the "on-line" office suites like Google Docs. (And gmail.) Before you entrust your documents to one of these services, make damned sure that you are able to retain local copies of your documents. (In fairness, most of them support this. But be sure they do, and be sure you know how.)

And for your own computer, choose an operating system and an office suite (and whatever else you use) that lets you retain full control of your files. Because they're yours.