Receivers can be the barriers (6)
I believe the answer is:
fences
I believe this is a double definition.
'receivers' is the first definition.
(receivers of stolen goods)
'the barriers' is the second definition.
(fence is a kind of barrier)
'can be' acts as a link.
(Other definitions for fences that I've seen before include "Avoids directly answering" , "Receives" , "Engages in swordplay or processes stolen goods" , "Good ones make good neighbours, it's said" , "Wooden barriers" .)