A Chief Security Officer (CSO) was notified that a customer was able to access confidential internal company files on a commonly used file-sharing service. The file-sharing service is the same one used by company staff as one of its approved third-party applications. After further investigation, the security team determines the sharing of confidential files was accidental and not malicious. However, the CSO wants to implement changes to minimize this type of incident from reoccurring but does not want to impact existing business processes. Which of the following would BEST meet the CSO's objectives?