You are a fool, and will be the first one to cry 'why didn't they do something? They spend all that money on spying, they should have known!'. There is simply no way to win with people like you, and it isn't until you get yourselves blown up in some terrorist activity that it occurs to you that there is a very real threat out there and they mostly want YOU dead.
Wake up! There are people in this world that want to kill you, and they will stop at nothing to accomplish that task. The very people that you are suspecting of covering something up are actually working night and day to keep you safe. Yes, they will make mistakes because that is what humans do. However, without them and their efforts, you will be very dead and we will go back to living in the 5th century as these whacked out terrorists want.
To believe the threat does not exist is nothing but wishful thinking. Get over yourself and deal with it.