...the FBI claims that Shapiro's multitudinous requests, taken together, constitute a "mosaic" of information whose release could "significantly and irreparably damage national security" and would have "significant deleterious effects" on the bureau's "ongoing efforts to investigate and combat domestic terrorism."
Disparate items of information, though individually of limited or no utility to their possessor, can take on added significance when combined with other items of information. Combining the items illuminates their interrelationships and breeds analytic synergies, so that the resulting mosaic of information is worth more than the sum of its parts.
...Gilligan argued that the government also believes the surveillance is legal under a 1979 Supreme Court case, Maryland v. Smith [sic], that found constitutional use of a “pen register” device to gather information on numbers called by a criminal suspect.
“In terms of computer technology, things have changed an awful lot since ’79,” Leon replied. “The technology used in that case pales in comparison — pales in comparison to the technology NSA has at its disposal to query hundreds of millions of records … maybe billions of records in a matter of minutes or hours.”
“Smith’s value may be very limited if at all in this case,” the judge added.