Proper support for journalist's text can stop others using it (9)
I believe the answer is:
copyright
'can stop others using it' is the definition.
(eg copyright prevents others using an idea)
'proper support for journalist's text' is the wordplay.
'proper' becomes 'right' (associated in meaning).
'support for' is a charade indicator (letters next to each other).
'journalist's text' becomes 'copy' (as in news copy).
'right' after 'copy' is 'COPYRIGHT'.
(Other definitions for copyright that I've seen before include "Sole entitlement to produce literary works" , "legal protection against piracy" , "control over reproduction" , "property of the author?" , "Protected" .)