Iranian Internet Controls – Targeting Flash and Email ?

Some very interesting investigations done by the Arbor Networks security folks looking into Iranian traffic engineering and filtering from the time of the Iranian presidential election onwards. They have both a preliminary investigation showing a dramatic fall in traffic at the time of the election and a follow up deeper look demonstrating that they appear to be specifically targeting streaming media (flash, et. al) and email, as graphically demonstrated by this graph:

Graph of video streaming bandwidth used by Iran around the time of the election.

Web and other traffic have been left relatively unscathed, prompting this comment:

Perhaps games provide a possible source of covert channels (e.g. “Bring your elves to the castle on the island of Azeroth and we’ll plan the next Ahmadinejad protest rally?”)