Took advantage of stunt by journalist (9)
I believe the answer is:
exploited
'took advantage of' is the definition.
('exploit' can be a synonym of 'take advantage of')
'stunt by journalist' is the wordplay.
'stunt' becomes 'exploit' (I've seen this before).
'by' is a charade indicator (letters next to each other).
'journalist' becomes 'ed' (short for editor).
'exploit'+'ed'='EXPLOITED'
(Other definitions for exploited that I've seen before include "Took advantage of" , "Made unfair gain from the weak" , "Ill-used" , "Used" .)