Yes, and they could've just gone to her and done it.
When the FBI served me with a subpoena they were waiting in the tube when I walked out of a plane. I'm sure they'd be capable of going even further to serve someone with a NSL.
Presumably the "matter of national security" has a time limit. That said, Applebaum and Snowden have seemingly managed to get comfortable enough without returning to their country of birth.
