Or, counter-counterpoint, everyone and their dog knows that Israel is spying on everyone and their dog, so all communications by people planning this shit are kept to in person or paper. Anything that has to be transmitted electronically likely is said in code phrases that are agreed on in person.

This has been standard practice for anyone involved in the intelligence world for over a century, so I would sure hope so!

It's still a huge intelligence failure, however, as infiltrating such groups is the primary focus of counter-intelligence organizations. This is also a long-standing practice, which is why all modern terrorist groups use compartmentalization to ensure nobody knows the entire plan.