What they don't say is that they have a lot of Arabs who are anons.
Anonymous are not a group with leaders and hierarchies. But they do have a few prominent members. Some are arabs, by the way. Most college students involved in the apartheid wall protests.
The rest of the anons are posers and wannabes. All it takes is for some arab anons to announce that they will hack Israeli sites and all the poses join in because they want to fit in and be cool.
Overall, they're a bunch of tools.