They broke the law 'with' (complete/total) 'impunity'. [=without fear of punishment; very freely and openly]
The rioters set fires and looted 'with impunity'.
(..) God knows, I hope it is the sons of Ragnar who have landed on our shores. For I have prepared a very special welcome for them. They're about to discover they can no longer attack us... with impunity. ~ Amen. ~ Amen. My Lord Bishop, let us go to war! "Behold, a people shall come from the north, (..)2017 TvShow: Vikings Title: Revenge Season: 4 Episode 18