A method of controlling a system of monitoring messages in a network is described. A message sent by a user of the network to one or more recipients is received and a weight is applied to any text from any previous message that appears in the message. A measure of language content used in the message is formed and stored in one or more data stores. Information identifying the sender of the message is also stored. The stored measure of the language content and the stored information identifying the sender is reported to an administrator of the system.