Sean Metcalf is the Chief Technology Officer at DAn Solutions, a company that provides Microsoft platform engineering and security expertise. Mr. Metcalf is one of about 100 people in the world who holds the elite Microsoft Certified Master Directory Services (MCM) certification. Furthermore, he assisted Microsoft in developing the Microsoft Certified Master Directory Services certification program for Windows Server 2012. Mr. Metcalf has provided Active Directory and security expertise to government, corporate, and educational entities since Active Directory was released. He currently provides security consulting services to customers with large Active Directory environments and regularly posts useful Active Directory security information on his blog, ADSecurity.org. Follow him on Twitter @PyroTek3.