Circle jerking: A group of people discussing a (usually controversial) topic with the same stance, agreeing with each other to the point of redundancy. Usually involves ego-stroking and the false satisfaction of having won an argument when in fact there was no opposition, or the opposition was boo'd out of the discussion.

Example: what happens on Facebook when people discuss either a)the awesomeness of religion or, b)the evils of religion.

Now you know, (citation needed).