The sniper was apparently doing official war duties,but the word "sniper" simplyhas a negative connotation,usually associated with a "lone wolf" tupe of person taking pot-shots @ people.Apparently,this is not the case,but the word "sniper" simply hasn egative connotations.Should they have given the movie a different name or did they want the controversy it might cause? That's Hollywood!
http://www.thegatewaypundit.com/2015/01/leftists-spray-paint-murder-on-american-sniper-billboard-in-la/