A three-day general strike is taking place in Iran this week. It's a show of defiance, as the anti-regime protest movement approaches its three-month mark with no sign of abating. On Monday, the strike was observed in dozens of Iranian cities, from the capital Tehran to Isfahan, Tabriz and the Kurdish regions. Facing its greatest existential challenge since the 1979 revolution, the Iranian regime has responded with a crackdown. Hundreds of people have been killed and thousands more arrested, including 11 sentenced to death.