Possibly so, though if you believe this, presumably the powers that be would not be above fabricating such evidence.<p>Bear in mind that the data used in this article are from arrest records. In fact, many of the arrests supposedly resulting from online activity could just as easily have occurred because of reports by concerned citizens. Would you put it past the authorities to seize a suspected terrorist identified through dragnet surveillance without creating a record of arrest? I think it is not inconceivable.<p>If you are opposed to mass surveillance, I think the best argument is that its social costs surpass the benefit of reducing terrorism. But perhaps this is not such a palatable argument after two well-publicized tragedies.