As companies review their dependence on cloud computing in light of the prolonged outage last week in Amazon's popular EC2 offering, once more the old doubts arise. Is the cloud a safe place for our finance department --- or any department -- to put its most critical information? How much internal or external backup do we need?

The when the failure knocked sites like Foursquare, Reddit, and Quora offline. Not much direct threat there. But the impact then spread to many hundreds more Amazon cloud customers, including, of course, corporations.

While much of the cloud's appeal has been the soft, welcoming image created by purveyors, CFOs rarely are a gullible lot. Rather, they've been looking for security vulnerabilities all along -- and finding them and correcting them. Reliability of service was always a worry. But analysis is showing in the wake of Amazon's failures that .

Now, as , finance executives will certainly be interested in what they find. But it's unlike to hold off the inevitable move toward cost-efficient cloud computing; rather, it will make CFOs more alert than ever about the need for risk management in IT.

See also this , and this report on important Forrester research.