It's capable of bringing the viewers together to spy on informer (3,7)
I believe the answer is:
eye contact
'it's capable of bringing the viewers together to spy' is the definition.
I don't know anything about this answer so I can't tell whether it can be defined by this definition.
'on informer' is the wordplay.
I cannot quite see how this works, but
'on' is found in the answer.
This may be the basis of clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for eye contact that I've seen before include "direct observation?" , "Communication" , "Exchange of views" , "shared vision" .)