Disruptions in Server / Data Center Market
Institutions like banks for many years now keep  back-up archives of their data in physical locations owned and operated by other legal entities. This is a standard case of outsourcing to specialists a requirement of a business process that is not a directly value-added activity. So the "sole custodian of one's own data" has been proven in the market not to be strong enough against cost-reduction considerations (or against price/value optimization if you wish).  

Cloud computing is comparatively still new. The cost incentives to adopt it are indeed very strong. In practice, I believe we will observe, as in the past with other innovations, a certain degree of selectiveness: as the risks and rewards of cloud-computing will become more well understood (and measured), companies may select certain parts of their activities to keep off the-cloud, while enjoying the cost reductions for all the rest. 

This by the way, can be squarely put in the framework of the, dear to us economists, marginal optimization - it is not a "yes-or-no" decision but a process where each company will adopt the Cloud up to the degree where marginal benefit equals marginal cost.