+1 I really want this feature. It is simply not enough to provide a screen saver password. I have kids that access my computer for various things. Mostly school stuff , Netflix and youtube. And that god forsaken Mine Craft. I have notes that pertain to business, diaries and some notes that are adult in nature. I don't want kids that have access to my computer to also have access to my evernote. I would really love to have a password per notebook so that I can let kids use the evernote but not access the diary and other personal data. Please add this feature! Nothing complex. Just something that I can put a simple lock code on. The IPhone App allows a 4 digit code. . . That would be awesome on my Mac.