Case closed. Got a couple of hundred documents back in paper form. No computers returned. Apparently NSA is frightened that hard disks can be brought back to life again, after the most thorough forensic deletion has been carried out...hence they keep them and shred them into microbits and incinerate them...
see url: https://www.youtube.com/watch?v=AMIrmt9sZyY
For lecture by Diane Roark..