Prisoner provoked people on-line, getting restrained (10)
I believe the answer is:
controlled
'restrained' is the definition.
('control' can be a synonym of 'restrain')
'prisoner provoked people on' is the wordplay.
'prisoner' becomes 'con' (abbreviation for 'convict').
'provoked people' becomes 'trolled' (I can't justify this - if you can you should give a lot more credence to this answer).
'on' means one lot of letters go next to another.
'con'+'trolled'='CONTROLLED'
'line getting' is the link.
I am not very happy about this link. Some or all of it may belong to another bit of the clue.
Can you help me to learn more?
(Other definitions for controlled that I've seen before include "Regulated" , "Disciplined" , "under supervision" , "Supervised" , "Restrained" .)