Definition: A company moved to a cloud provider in a rush without fully understanding its advantages and without fully understanding the company's own disadvantages. The results are a catastrophic disruption to the company and a heavy financial cost.
Example: "We tried to move to AWS and now a dark cloud is hanging over us."
"Trying to make your own private cloud with X technology is just a dark cloud."
Companies rushing to adopt technology or migrate to platforms without understanding the full scope of the consequences? Happens every day and is happening across the hall from me right now.
A company deploying any kind of setup, cloud or not, while handling sensitive client data without having done any sort of risk assessment and due diligence is simply negligent and is a sitting duck. This does not require a fancy new term.