>the fact that none of these people were prevented makes me think the mass surveillance isn’t as scary as we thought This seems to presuppose that stopping the

>the fact that none of these people were prevented makes me think the mass surveillance isn’t as scary as we thought This seems to presuppose that stopping the attacks are the purpose of the mass surveillance, and its failure to do this proves that mass surveillance is ineffective and therefore harmless. But one could equally well conclude that the people in charge of mass surveillance aren't trying to stop attacks, and that is not what it is for. This is more scary, not less.