Determining sensitive information and preventing the unauthorized or unintended dissemination of such information are disclosed. Terms are determined from documents associated with users in a network. Distributions among users and relative frequencies with which the terms are used are determined. Link strengths between users are calculated. Based on the distribution of the terms, the relative frequencies of use among the user profiles and link strengths between users conducting information transactions that include the terms, a sensitivity level for each term can be determined. To determine whether a particular information transaction with particular terms may be conducted between two users in the network, a combination of link strength between the users and sensitivity level of the terms with respect to the users or users' profiles are considered. If the information transaction includes terms that are unknown to one of the users, then a warning or alarm can be raised.