(CNN) -- In the digital age, war isn't contained to the ground.
The Israeli government on Sunday said it has been hit with more than 44 million cyberattacks since it began aerial strikes on Gaza last week. Anonymous, the hacker collective, claimed responsibility for taking down some sites and leaking passwords because of what it calls Israel's "barbaric, brutal and despicable treatment" of Palestinians.
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"The war is being fought on three fronts," Carmela Avner, Israel's chief information officer, said on Sunday in a press release. "The first is physical, the second is the world of social networks and the third is cyberattacks.
"The attackers are attempting to harm the accessibility of Israel's government websites on an ongoing basis. When events like the current operation occur, this sector heats up and we see increased activity. Therefore, at this time, defending the governmental computer systems is of invaluable importance."
Social media takes on Gaza conflictTwitter as a weapon in GazaIsrael and the military wing of Hamas have been criticized for using ready-to-share images on social media to spread spin about the conflict, which has claimed the lives of about 100 Palestinians and three Israelis since the back-and-forth violence began again Wednesday.
There is some dispute about the effectiveness of the cyberattacks.
Israel says the attacks have largely been unsuccessful.
"We are reaping the fruits on the investment in recent years in the development of computerized defense systems, but we have a lot of work in store for us," Israel's finance minister, Yuval Steinitz, said in a written statement.
Reuters quotes him as saying only one website was down for 10 minutes.
Anonymous, meanwhile, posted a list of more than 650 Israel-based websites it says it has taken down or defaced since last week.
"They've knocked down websites, deleted databases and have leaked e-mail addresses and passwords," Casey Chan wrote Friday for the tech site Gizmodo. "It's a whopping takedown."
A post on an Anonymous Twitter feed Monday morning said another set of hackers had defaced the Israeli versions of several Microsoft websites, including Bing, MSN and Skype. Visitors to Bing's Israeli site on Monday morning saw an anti-Israel rant instead of a search-engine homepage.
"Microsoft is aware of the site defacements and working to get all sites fully functional," a company spokeswoman wrote in an e-mail to CNN. "At present, we have seen no evidence to suggest the compromise of customer information but will take action to help protect customers as necessary."
A page associated with Anonymous also posted a new threat: "November 2012 will be a month to remember for the (Israel Defense Forces) and Internet security forces. Israeli Gov. this is/will turn into a cyberwar."
Some observers took this as a sign of an escalating digital battle.
"Beyond mere 'denial of service' tactics that blocked sites with floods of junk data, the hackers also ramped up their attacks to penetrations of any vulnerable target available to them, resulting in tens of thousands of Israeli citizens' and supporters' private data dumped onto the Web," wrote Andy Greenberg from Forbes.
Others said most of Anonymous' threats have been "hollow" so far.
"Today, Anon lacks the talent and semi-cohesion it once boasted across the net, and its most recent online crusade is an embarrassing reminder," Sam Biddle wrote for Gizmodo on Monday. "This is less a war than the hacker equivalent of egging someone's house and then smoking weed behind a Denny's."
The group is calling its campaign #OpIsrael.
"While the Israeli government almost certainly has backups of the aformentioned databases, these attacks as well as the defacements show Anonymous isn't just doing its usual spree of overloading target sites," writes another tech blog, TheNextWeb.
"OpIsrael appears to have gotten multiple hackers involved who are interested in doing actual damage, or at least something that is slightly more permanent than just a 404," which is the code that appears online when a website won't load.
Greenberg, from Forbes, makes the important point that none of this digital damage compares to the loss of life on the ground in the Middle East.
"Anonymous' attacks, of course, hardly register compared with the physical damage inflicted by both sides in the Gaza conflict," he wrote.