Network security professionals are besieged by a nonstop flood of new software vulnerabilities, easy-to-get hacker toolkits, and an army of technology criminals eager to exploit network weaknesses for fun or profit. And despite defensive efforts with firewalls, intrusion detection, antivirus and the like, criminals, careless employees and contractors have exposed more than 158 million digital records of consumers' personally identifiable information since 2005. Clearly, a more comprehensive defense-in-depth strategy is required. Core to this approach, security professionals are turning to continuous vulnerability management to find and quickly fix weaknesses in network security, and to document compliance with security and consumer privacy regulations. This security guide describes these requirements and on demand software-as-a-service (SaaS) solution called QualysGuard for effective vulnerability management and policy compliance.