1. A method for deriving user expertise in a network environment, comprising: receiving at a network sensor coupled to a central engine comprising a processor and a memory element data propagating in the network environment; evaluating at the network sensor one or more fields in the data, wherein the evaluating includes searching and filtering for nouns and noun phrases; identifying selected terms within the nouns and noun phrases, wherein the selected terms correspond to one or more topics, wherein the selected terms are tagged by a central engine with respective expertise tags; identifying at the network sensor in real time a first user who generated the data and a second user who consumed the data; adding the selected terms to a first personal vocabulary of the first user and a second personal vocabulary of the second user, wherein the first personal vocabulary is associated with expertise of the first user in the one or more topics and the second personal vocabulary is associated with expertise of the second user in the one or more topics, wherein the selected terms are assigned a higher weight in the first personal vocabulary than in the second personal vocabulary; and associating the first user and the second user with the expertise tags.