The Israeli military issued the world's first announcement of a military campaign via Twitter today with the disclosure of a large-scale, ongoing operation in Gaza. The Twitter announcement was made before a press conference was held.
A major Israeli military campaign in the Gaza Strip was announced today via Twitter in lieu of a formal press conference. The Israeli Defense Forces' official @IDFSpokesperson Twitter feed confirmed “a widespread campaign on terror sites & operatives in the #Gaza Strip,” called Operation Pillar of Defense, at approximately 9:30 a.m. Eastern time. Shortly before the tweet, Hamas' military head Ahmed al-Jabari was killed by an Israeli missile strike--Israel's military claims al-Jabari was responsible for numerous terror attacks against civilians. The IDF announcement on Twitter was the first confirmation made to the media of an official military campaign.
The Israeli military incursion follows months of rising tension in Gaza and southern Israel. More than 100 rockets have been fired at Israeli civilian targets since the beginning of November 2012, and Israeli troops have targeted Hamas and Islamic Jihad forces inside Gaza in attacks that reportedly included civilian casualties. According to the IDF spokespersons' office, the Israeli military is “ready to initiate a ground operation in Gaza” if necessary. Hamas' military wing, the Al-Qassam Brigades, operates the @alqassambrigade Twitter feed, which confirmed al-Jabari's death.
Fast Company 
