One of the main purposes of a security policy is to clearly define the company's expectations so you do have legal recourse when an employee goes against the policy. You do need to show that the policies were effectively communicated to the end user and they were aware of the policy they disobeyed, or at least claim to have known (such as signing a document that they have read and understood the company's security policy). As for reference cases, the E-Policy Handbook by Michael Overly contains some excellent examples.
For more information on this topic, visit these other SearchSecurity.com resources:
Security Policies Tip: Creating an information security policy
News & Analysis: Dos and don'ts for policing user policies
Best Web Links: Security Policies and Infrastructure
Dig Deeper on Information Security Policies, Procedures and Guidelines
Have a question for an expert?
Please add a title for your question
Get answers from a TechTarget expert on whatever's puzzling you.