According to the present invention, there is provided a method and apparatus for controlling an access for a client application residing on a user computer to data stored on a network computer within a network. The method comprises the steps of receiving a request from the user computer for accessing the data; retrieving the data from the network computer and storing it in a memory; deriving from the stored data at least one attribute that relates to the content of the data; and deciding based on the derived at least one attribute whether or not the data stored in the memory is provided to the user computer