Harmless meme or data mining?

If you use any kind of social media, by now you've probably seen the "how hard did aging hit you" meme floating around.  People post a photo of themselves back in 2009 (or earlier) next to a current photo.

Last semester, I took an information security class, and since then, I've been more acutely aware of what information I post online.  This article from Wired raised some interesting points.

Conan O'Brien says the years have not been kind to him.