1. A method of detecting unwanted conversational media sessions, said method comprising: obtaining a sequence of significant attributes directly from a bit-stream corresponding to a real-time conversational media session; evaluating similarity between the sequence of significant attributes associated with the real-time conversational media session and same significant attributes corresponding to a reference data item taken from a previous conversational media session and output an evaluation result; and determining based on the evaluation result, whether the real-time conversational media session is wanted or unwanted.