Anonymous hacktivist today have started attacking Israeli based websites leaving them defaced. The attacks are in light to the on going attacks on the Gaza strip which are taking place right this moment as i type. Over the past hours there has been word that Israel plans to shut down Internet and in light of this anonymous have stepped up, released a "Care package" which is said to contain a possible way and information on how to stay connected to the Internet. The attacks by the hacktivist so far have been on only a few sites one of which is Israeli security and surveillance company falcon-s.co.il and the deface message leaves one clear message.
Stop bombing Gaza!! Millions of Israelis & Palestinians are lying awake, exposed & terrified. We Anonymous will not sit back and watch a cowardly Zionist State demolish innocent people’s lives. We have taken down your top security and surveillance website down.
Other sites that have been defaced so far are advocate-israel.com, https://danybarshay.co.il, https://deplus.co.il, https://filtuna.co.il iconcept.co.il, https://iiamo.co.il, https://littner.co.il as well as www.connectionsmag.co.il which has had its database leaked again. 
Press release for OpIsrael > Anonymous Operation Israel – Press Release Thursday – November 15, 2012 2:00 AM ET USA Greetings World — For far to long, Anonymous has stood by with the rest of the world and watched in despair the barbaric, brutal and despicable treatment of the Palestinian people in the so called "Occupied Territories" by the Israel Defense Force. Like so many around the globe, we have felt helpless in the face of such implacable evil. And today’s insane attack and threatened invasion of Gaza was more of the same. But when the government of Israel publicly threatened to sever all Internet and other telecommunications into and out of Gaza they crossed a line in the sand. As the former dictator of Egypt Mubarack learned the hard way – we are ANONYMOUS and NO ONE shuts down the Internet on our watch. To the IDF and government of Israel we issue you this warning only once. Do NOT shut down the Internet into the "Occupied Territories", and cease and desist from your terror upon the innocent people of Palestine or you will know the full and unbridled wrath of Anonymous. And like all the other evil governments that have faced our rage, you will NOT survive it unscathed. To the people of Gaza and the "Occupied Territories", know that Anonymous stands with you in this fight. We will do everything in our power to hinder the evil forces of the IDF arrayed against you. We will use all our resources to make certain you stay connected to the Internet and remain able to transmit your experiences to the world. As a start, we have put together the Anonymous Gaza Care Package – https://bit.ly/XH87C5 – which contains instructions in Arabic and English that can aid you in the event the Israel government makes good on it’s threat to attempt to sever your Internet connection. It also contains useful information on evading IDF surveillance, and some basic first aid and other useful information. We will continue to expand and improve this document in the coming days, and we will transmit it to you by every means at our disposal. We encourage you to download this package, and to share it with your fellow Palestinians to the best of your ability. We will be with you. No matter how dark it may seem, no matter how alone and abandoned you may feel – know that tens of thousands of us in Anonymous are with you and working tirelessly around the clock to bring you every aid and assistance that we can. We Are Anonymous We Are Everywhere We Are Legion We Do Not Forgive We Do Not Forget To the oppressors of the innocent Palestinian people, it is to late to EXPECT US
This is not the first time anonymous have done this, before hacker collective Team Poison and Anonymous hacktivist joined forces to attack Israeli based sites in the name of OpFreePalestine. At the time of publishing live streaming of the on going attacks on gaza can be viewed here and here