Some confront a rioter somewhere in Canada (7)
I believe the answer is:
ontario
'somewhere in canada' is the definition.
(Ontario is a province of Canada)
'some confront a rioter' is the wordplay.
'some' says the answer is hidden in the clue (some parts of the word are used).
'ONTARIO' is hidden within 'confront a rioter'.
(Other definitions for ontario that I've seen before include "One of the Great Lakes" , "Smallest of the Great Lakes" , "Most populous Canadian province" , "Oration in Canadian province" , "Root in a Great Lake" .)