#OpIsrael is an organized set of attacks aimed at Israeli Web sites, which was officially first launched on 14 November, 2012 against the Israeli government, public institutions and other high profile Web sites.
The goal of the attackers was to a launch massive set of cyber-attacks against Israeli cyber space. Their main intent was to advertise opposition to Israel's actions in Gaza. The organized attacks were planned by several Muslim hacktivist groups such as “Parastoo” (Iran), “AnonGhost” (Tunisia), and “Red Hack” (Turkey).
Those groups are planning another scheduled #OpIsrael set of attacks for April 7, 2014.
There is very little solid information about the expected and specific attacks. The prediction is that the attacks will not be significant and will be different from last year. However, best practice does require organizations be ready for any possibility.