Do people learn to become violent or aggressive just by watching/observing violence on TV, video games, and/or internet?

Brown vs. Entertainment Merchants Association

1- Do people learn to become violent or aggressive just by watching/observing violence on TV, video games, and/or internet?

(Also look up and read Brown vs. Entertainment Merchants Association, 564 U.S. 786( 2011).

What are your personal thoughts on this?