All the eavesdropping is completely dumb, even the less technical of all terrorists can just change a word for another and all your billion dollar security goes to the dump. Example: when they talked personally they agreed girl=bomb

Their texts will look like:

- my girl is not with me, I left her at discowild

- nothing happened mate, no idea why?

- relax fam, ask mike to present you another girl, he is partyng next to dominoes. We getting wasted today tho, no bs

And now is completely impossible to differentiate that conversation from all the other 10 billions texts that happen at any Saturday night.