1. A method for generating alerts, comprising: receiving a set of alert rules; associating the set of alert rules with a topic vector, wherein the topic vector is a representation of semantic significance of one or more terms; categorizing a set of messages based at least in part on analysis of the set of messages against the topic vector; retrieving the set of alert rules to be applied to the categorized set of messages, wherein the alert rules define one or more thresholds that trigger one or more alerts; determining if the categorized set of messages satisfy the one or more thresholds defined in the alert rules; and if the one or more thresholds are satisfied, generating a corresponding alert of the one or more alerts.