GREEN MOVEMENT – 2009, Iran – Mass demonstrations erupted after the June 2009 presidential election that saw a landslide victory for Mahmoud Ahmadinejad. Opposition reformist candidate Hossein Mousavi claimed the vote results were fraudulent. Protests were organized and escalated by leveraging the Internet and mobile phones, in particular the social media site Twitter. Much news coverage of the harsh government crackdown and ensuing violence was circulated via 'tweets,' giving this uprising the alternative name, 'The Twitter Revolution.' Iranian security personnel gather during a march in Tehran, Iran, on June 20, 2009 in this photo uploaded to Twitter. Reuters and other foreign media are subject to Iranian restrictions on leaving the office to report, film or take pictures in Tehran.