All the news orgs doing it. BBC:

The soles of shoes are considered the ultimate insult in Arab culture.

CNN:

Hurling shoes at someone, or sitting so that the bottom of a shoe faces another person, is considered an insult among Muslims.

The New York Times (from an earlier shoe-throwing episode):

During the argument, heated words were exchanged and shoes were thrown, a severe insult in the Arab world.

This persistently stupid meme has been harped upon by The Angry Arab for quite some time now.