In Facebook’s early days, everything you put on the site was shared with your friends. So it was not “private, personal, info” but rather the opposite — information that users wanted to publicize widely. I have never put anything on Facebook that I care whether Mark Zuckerberg reads or not. It would be weird and creepy, for sure, if he was looking at pictures of my baby, but I willingly shared those with over a thousand people so am happy to share with one more.