People in the know -- are they not out and about? (8)
I believe the answer is:
insiders
This clue is a double definition.
'people in the know' is the first definition.
(people with inside knowledge)
'are they not out and about?' is the second definition.
(ie people who aren't outside)
(Other definitions for insiders that I've seen before include "Those privy to info" , "those with an advantage" , "Prisoners perhaps" , "people with specific knowledge?" , "They have an edge" .)