I would disagree with this reasoning.<p>Yes, french HUMINT has heavily infiltrated extremist organizations, and failed to prevent this attack. It does not mean that it was the use of encryption that allowed ISIS&#x2F;extremist organizations to execute this attack on french soil.<p>The french secret service approach is fundamentally different from the US, as they historically rely less on SIGINT.<p>I am not sure where I read it, but in presume the number of prevented attack is in the thousands.