Granted, you can't really call McAfee a cloud vendor. McAfee's play is sort of the cloud model in reverse; instead of customers placing important assets on McAfee's cloud, customers download and install McAfee's software on their important assets -- desktops and servers -- and trust McAfee to issue updates without manual supervision. McAfee betrayed that trust in the worst way possible: It took down thousands and thousands of customer systems.

The same thing can and will happen to cloud vendors and their customers, but the damage could be far worse. While the McAfee debacle caused primarily Windows XP SP3 desktops and workstations to crash, servers and the corporate data stored on them were unaffected. If a similar situation were to happen to a real cloud vendor, the situation would be reversed. The time and aggravation required to reimage, repair, or reinstall hundreds or thousands of corporate desktop pales in comparison to the specter of massive data loss or long-term application and resource unavailability due to third-party problems. This should worry anyone who places trust in any cloud they don't control.

More: http://pcworld.com/article/195004/