I see memes about once a week which state, "The media isn't covering this really important thing. Shouldn't they be ashamed! Like and Share and FWD to grandma if you agree!". Similar posts include "conservatives don't want you to see this" or "liberals are hiding this important news from us". 

I find this line of reasoning insulting to the very issue at hand. Instead of talking about the apparently important topic, the meme creator and reposters are just using it as a hammer against an outside group. They seem to care more about beating the other group rather than supporting their purported important cause.

What is the name of or term for this argumentative tactic?