It's my understanding that the number of FISA apps that were "modified" by the FISA Court from 2001 to the present is more than the number "modified" in all the previous years combined. Whatever "modified" means.
I don't know either. I have a vague picture of administrative "promises" about the use of intelligence gleaned, in order to separate the use of intelligent in a "foreign intelligence" sense (e.g., terrorism prevention), vs. for crime prevention or prosecution.