Actually, they used to. Then they wised up and started using couriers. Both worked to the disadvantage of Al Quaida. When they stopped using electronic communications their organization suffered. Then, it was the movements of a courier that gave away Bin Laden.
So, regardless of whether you think it's OK for the NSA to spy on everyone, this push did break down Al Quaida's organization.
Whether it affects cell oriented terrorism (or 'lone wolf' terrorism) is another matter. For example, for the Boston bombers one of them did mention something about terrorism and came on the radar, but the FBI misjudged the threat.
So, regardless of whether you think it's OK for the NSA to spy on everyone, this push did break down Al Quaida's organization.
Whether it affects cell oriented terrorism (or 'lone wolf' terrorism) is another matter. For example, for the Boston bombers one of them did mention something about terrorism and came on the radar, but the FBI misjudged the threat.