AP Photo

Once again, tear gas hangs over Tahrir Square. For the third straight day, Egyptian activists, ordinary citizens, Islamists, and soccer hooligans called the "Ultras" battled the Central Security Forces (CSF) -- paramilitary troops under the command of the Ministry of Interior. The revitalized protest movement has prompted suggestions that Cairo may be on the verge of another revolutionary wave, similar to the one that overthrew Hosni Mubarak in February.