An information management system is described comprising one or more workstations running applications which allow a user of the workstation to connect to a network, such as the Internet. Each application has an analyzer, which monitors transmission data that the application is about to transmit to the network or has just received from the network, and which determines an appropriate action to take regarding that data. The analyzer may consult policy data containing a supervisor-defined policy to govern the workstations in order to determine what action to take. Such actions may be extracting data from the transmission data, such as passwords and usernames, digital certificates or eCommerce transaction details for storage and record keeping; ensuring that the transmission data is transmitted at an encryption strength appropriate to the contents of the transmission data; determining whether a check needs to be made as to whether a digital certificate received in transmission is valid; determining whether a transaction about to be made by a user of one of the workstations needs third party approval before it is made; and controlling the transmission of messages, such as e-mails according to a policy.