Securing Web applications is the No. 1 problem facing security professionals today. With 162 million Web sites in existence and millions more popping up each month, the sheer size of the problem is staggering -- not to mention the fact that nine out of 10 Web sites have serious vulnerabilities that can put critical customer data at risk. In fact, a new malware-infected Web site is discovered every 14 seconds. So, why aren't more companies solving this problem?