Data surveillance techniques are presented for the detection of security issues, especially of the kind where privileged data may be stolen by steganographic, data manipulation or any form of exfiltration attempts. Such attempts may be made by rogue users or admins from the inside of a network, or from outside hackers who are able to intrude into the network and impersonate themselves as legitimate users. The system and methods use a triangulation process whereby analytical results pertaining to data protocol, user-behavior and packet content are combined to establish a baseline for the data. Subsequent incoming data is then scored and compared against the baseline to detect any security anomalies. A centroid representing the normal population of the data packets is identified. The design allows establishing the context of various events of interest in the organization, thus enabling dynamic management of security policies.