I would definitely say that those who inflict negative influence.
We could live in a world where no negative influence never existed. People could just stop doing that. Then you'll see that everybody is nice, and that there's no more fighting.
One good example of this is a child being exposed to his/her parents child abuse. These parents will yell at, insult, and make fun of their child.
What happens after that? The child starts doing the same thing to other people, thinking that their parents raised them that way, so that must be the right thing to do in life.
Another example could be constant bullying. One child could be exposed to so much bullying in one school that they'll start getting "used to it" and do the same thing to others.
To be blaming the people who are negatively influenced by the negative influencers should feel ashamed.