The detection rule for "O365 Compliance Content Search Started" is designed to monitor and alert on instances where a compliance content search is initiated within the Office 365 Security and Compliance Center. This is accomplished through tracking the 'SearchCreated' operation within the 'o365_management_activity' logs related to the SecurityComplianceCenter workload. Initiating such a search is a critical activity as it may signify attempts to probe or access sensitive organizational data, which includes emails and documents. If this action is flagged as malicious, it can raise concerns over unauthorized data access, potential data exfiltration, and thus, compliance violations. Effective monitoring of these activities is essential to uphold the integrity and security of an organization’s data assets.