In the week, the banks' websites have been intermittently bombarded with a flood of requests that left their own customers unable to reach them and perform financial transactions via internet banking.
According to the statement posted online by the self-styled Izz ad-Din al-Qassam Cyber Fighters group, the attacks are a way of forcing the takedown of the controversial video that, according to the group, mocks the prophet Muhammad.
The hacktivists have also provided links to two sites that, when visited by volunteers, automatically use their computers to flood the aforementioned sites with requests.
But, according to some security researchers, that alone isn't enough to effectively execute these attacks - the financial institutions in question have DDoS services at their disposal that could easily make those efforts meaningless.
They believe that the hacktivists are taking advantage of existing botnets that are offered for rent on the Internet, and that behind all these efforts might be a nation-state - possibly Iran.
Other researchers - namely Dmitri Alperovich, cofounder and CTO of security company CrowdStrike - believes that the real reason behind the attacks is not the fact that the groups wants the video taken down, but that they want to prove to the world what they are capable of.
Given the (in the Middle East) ubiquitous view that the U.S. cares only about the money, targeting its biggest financial institutions could be an attempt to hit the country where it hurts the most.