Easy, big guy. That is what they want to do. They think if you get angry and annoyed, they have won. It doesn't matter if they are right or wrong. They post simply to get a reaction. No reaction and they will go away. In psychology class, they referred to this type of behavior as the need for reinforcement. It doesn't matter whether the reinforcement is positive or negative, only that it happens. This makes the one needing the reinforcement feel important, even though he is really not. Little children are more likely to need reinforcement than adults, as most adults feel secure about who and what they are. Little children don't.
Relax and ignore them. Facts mean nothing to them, only your reaction.