Given the ease with which many magazines and newspapers have managed to get explosives and weapons through all the security checkpoints at major transportation

Given the ease with which many magazines and newspapers have managed to get explosives and weapons through all the security checkpoints at major transportation centers, the total shock the west was in during all the different transitions of power and politics during the "Arab Spring", and the complete lack of warning the West had for the terrorist attacks we've seen, isn't it more likely that like many experts claim, very little if any terrorist attacks have actually been stopped by all this spying?