Absolutely. But computers and centralized data make physical security easier. Old fashioned typewriters, paper files, and manual indexes for searches are safer (for very specific things), because you simply just can't haul all of it out. For a decent set of paperwork you'd spend months or years xeroxing everything. Leaks may happen but may be smaller. Processed and redacted data may still be put on computers for searching. It's a tradeoff with obvious serious disadvantages, but one that can save the operations and even lives of the good guys.