An anonymous reader writes "Tehran's leadership faces its biggest crisis since it first came to power in 1979, as Iranians at home and abroad attack its legitimacy in the wake of June's allegedly rigged presidential vote. An opposition effort, the 'Green Movement,' is gaining a global following of regular Iranians who say they never previously considered themselves activists. The regime has been cracking down hard at home. And now, a Wall Street Journal investigation shows, it is extending that crackdown to Iranians abroad as well. Part of the effort involves tracking the Facebook, Twitter and YouTube activity of Iranians around the world, and identifying them at opposition protests abroad. People who criticize Iran's regime online or in public demonstrations are facing threats intended to silence them."