> "...captured using intelligence generated from..." is another of those trick phrases.
> It doesn't clearly imply that without the program they wouldn't have captured those terrorists.
Those are excellent points, and I wish they were raised more often. I'd like to add one more: How many of those captured were terrorists only thanks to your own government setting them up for the task first? In other words, how much of this was the result of "manufactured terrorism", ála FBI? (ref: http://www.motherjones.com/politics/2013/01/terror-factory-f... and the earlier article linked from the story.)
After all, the actors in those programs still needed to communicate. Judging by the two articles the subjects weren't particularly bright either, so they probably would not have known how to protect their communications. Thus they were bound to generate material that would be scooped up the NSA programs. The fact that the plots were not only known in advance, but planned by your own government officials simply ensured that they would know with perfect accuracy where to look and what to look for.
A naked figure of "300 terrorists captured" is therefore meaningless, just like you said. Without a futher breakdown, the figure just feels like marketing.
As an odd side note - this makes manufactured terrorism look a bit like astroturfing. A scary thought.