REDUCTION OF UNSOLICITED INSTANT MESSAGES BY TRACKING COMMUNICATION THREADS

PROBLEM TO BE SOLVED: To reduce spam over instant messages (SPIM).SOLUTION: The number of open instant messaging threads that a particular user can have at a point in time is limited to prevent a potential spammer from flooding instant messaging users with SPIM. The technique of limiting the number of the open instant messaging threads is combined with a user feedback technique that allows a user to inform an instant messaging service or the like of another user who is sending SPIM or other undesirable contents, or a text analysis technique that allows the instant messaging service or the like to analyze texts generated by a user and to determine whether the user is sending SPIM or other undesirable contents to other instant messaging users or not.