It is also important to note that Microsoft is not offering shared kernel on Azure using their new container technology because they believe it is too insecure.

It is also important to note that Microsoft is not offering shared kernel on Azure using their new container technology because they believe it is too insecure. Microsoft might be a special case because their kernel has an especially large surface area. But I think the current cloud providers that are providing shared kernels are walking a very fine line when it comes to security. Seccomp obviously mitigates this problem and probably puts you in a better position than using a hypervisor if you lock things down very aggressively.