As defined in The Coming Wave:
Definition
How do we keep a grip on the most valuable technologies ever created as the become cheaper and proliferate further (The Law of Technology). Creators very quickly lose control of their invention. Henry Ford would not be able to stop a car accident today.
This is closely related to the idea of Alignment in AI;
Alignment
How do we align the intentions of models more powerful than humans with the intentions of humans?
Does containment ever work?
Take nuclear weapons. They never really proliferated (or were in huge demand by the common public). There were serious efforts in reducing its proliferation because of Mutually Assured Destruction.