Friend shielding revolutionary hacker (7)
I believe the answer is:
machete
'hacker' is the definition.
(blade used to hack at things)
'friend shielding revolutionary' is the wordplay.
'friend' becomes 'mate' (mate is a kind of friend).
'shielding' indicates putting letters inside.
'revolutionary' becomes 'Che' (Che Guevara).
'mate' going around 'che' is 'MACHETE'.
(Other definitions for machete that I've seen before include "Jungle chopper" , "The mace (anag.)" , "Large heavy knife for cutting vegetation" , "Broad heavy knife used in S American jungles" , "cutter" .)