I dislike this article because it asserts that the NSA has ever said "a lot of terrorists use X, Y and Z." In reality, the NSA has said "tracking this data w.r.t. terrorism doesn't always prevent terrorist crimes, but it has been successful in the past." It seems like nonsense to assert that none, zero, nil terrorists use these services... I agree with Arnor in his comment - this is a trivializing report.
“We would love for this to be rolled out to every high school in America,” said Carson. “But we wanted to fix a couple schools, go deep, and really understand if it works.”