The sad part is, there's really nothing that can be done to prevent this sort of attack. There's no way to catch everyone on the planet with the desire to commit these attacks, there's no way to moniter everyone on the planet so you can see attacks coming, and by the time you notice what they're doing it's too late. This is one of the reasons I'm against organized religeon. Only something that causes humans to believe in what can't be proved could convince them to kill others in a suicide attack for... well, whatever damn reason they're being told is worth dying for. I really wish I knew a good way to prevent this type of thing, but as far as I can see the only options we have are giving up our personal freedems until we don't have anything left worth protecting just to keep ourselves safe, or accepting that a cetain amount of terrorist attacks are inevitable. At least we can say that this is nothing compared to what they have to deal with in a place like Isreal.