Protest from mean rotters going berserk (11)
I believe the answer is:
remonstrate
'protest' is the definition.
(thesaurus)
'mean rotters going berserk' is the wordplay.
'going berserk' is an anagram indicator.
'mean'+'rotters'='meanrotters'
'meanrotters' is an anagram of 'REMONSTRATE'.
'from' acts as a link.
(Other definitions for remonstrate that I've seen before include "Make a forceful protest" , "Make a forcefully reproachful protest" , "Argue fiercely" , "Argue in protest" , "Take issue with" .)