Seriously. Call me pedantic, but the lack of (correct) apostrophe use makes trying to read online really annoying.
The joke is there’s always an XKCD for something. I keep seeing Oatmeal links pop up too, so maybe they want to add themselves to that little rule. And, oddly, I couldn’t turn up an XKCD that handled the apostrophe. I did find this, which is both funny and basically true, but no Munroe take on the bane of online writing.