One of the key challenges in cloud computing is its distributed environment and dispersed data centers across the globe. It is very difficult to trace data location in public clouds.
Therefore. Assurance of data location is key advantage of private cloud.

Containers are code execution environments that run within an operating system(for now), sharing and leveraging resources of that operating system. While a VM is a full abstraction of an operating system, a container is a constrained place to run segregated processes while still utilizing the kernel and other capabilities of the base 0S.
Ref: CSA Security Guidelines V4.0

In a shared responsibility model. Data security is responsibility of the cloud consumer and he is legally liable.