I am forever reminded that the /sarc tag should always be used no matter how obvious the post.
John Kerry was/is/evermoreshallbe a liar.
I am always amazed when some dullard looks at something so obvious and proceeds to take you to task for joke.
On the other hand, some folks are so full of their own self importance, and so needful to impress you with what they know, that they pretend not to see the joke and spout off with their subject knowledge.