What is a common technique to secure confidential data from insider threats?

Limiting and controlling access is a highly effective technique to secure confidential data from insider threats. This approach ensures that only authorized personnel have access to sensitive information, thereby reducing the risk of unauthorized access and potential data breaches. By implementing role-based access control and the principle of least privilege, organizations can tightly manage who can view or interact with confidential data. This not only mitigates the risk posed by malicious insiders but also minimizes potential accidental exposure or misuse by well-intentioned employees.

The other methods present challenges or vulnerabilities. Storing passwords in a folder does not provide proper security, as it could easily lead to unauthorized access if the folder is compromised. Encrypting data that's in use offers a level of security, but if not managed properly, it can still be vulnerable to access by those who shouldn't have it. Storing sensitive data on a networked computer increases exposure to potential attacks, as networked devices are more susceptible to breaches. Thus, the most proactive approach to protecting against insider threats is to ensure robust access controls are in place.