Took advantage of American journalist (4)
I believe the answer is:
used
'took advantage of' is the definition.
(I've seen this before)
'american journalist' is the wordplay.
'american' becomes 'US' (United States).
'journalist' becomes 'ed' (short for editor).
'us'+'ed'='USED'
(Other definitions for used that I've seen before include "Sued (anag.)" , "was milking" , "worked unfairly" , "Put to a purpose" , "Was treating" .)