The Wall Street Journal has a corresponding article about this story. In that article, the Instagram founders' names are written, "Messrs. Systrom and Krieger..."
Despite frequently reading both papers, I can't recall ever seeing "Messrs" before. I thought it was a typo at first; turns out it's a formal way to refer to two or more men instead of saying Mr. several times. This isn't germane to the story at hand at all, but I found it to be an interesting and educational part of reading both articles about the same story.