The problem: In 2004 the Hamilton County Court in Cincinnati discovered that the Social Security numbers of drivers who'd received speeding tickets were posted on its website. Elsewhere, private data has been cloaked - but easily revealed - in the HTML code embedded in companies' customer service pages. Worse, a common security hole called an SQL injection vulnerability enables hackers to slice into your back-end database. Resulting security breaches have triggered FTC actions against firms such as Petco and Guess Jeans.

The solution: Know your site - how it works, how it manipulates data, and how it displays it. If it's too big to traverse in a day, hire experts to audit your exposure to security holes like cross-site-scripting vulnerabilities and SQL injection attacks.