Well, the two perpetrators of the Boston Marathon bombing have been identified, one killed and the other desperately on the lam and probably cornered in Watertown, Massachusetts.
In this day of nearly universal security cams in urban areas and almost everyone having a photo/video camera on their person, it's almost impossible to conduct a terrorist act and expect to get away with it unidentified and unscathed. It's rough trying to engage in skullduggery undetected anymore.
Of course, the flipside is that everyone's activities are being recorded much of the time, at least in urban areas. "There's no privacy when you are in public" is the truism, but it's starting to come home that the bad guys, be they terrorists or armed robbers, are finding it harder and harder to perpetrate their crimes unobserved.
Six of one, half a dozen of the other,.