This first portion of the presentation will explore the emerging cyber threats facing the industrial control systems network environments with a focused look at the Power & Utility industry. It will then discuss the challenges faces advanced technical testing (i.e., Attack & Penetration Testing and Red Teaming) within this environment. The first section concludes with a discussion of current testing approaches and in the face of the above challenges, why testing remains an important capability in this space. The second portion of the presentation will present a proposed approach for performing Advanced Testing Services in this environment as well as discussing the legal and security implications of testing in this environment.