Maybe I'm not being clear on this: I don't have multiple computers and multiple accounts. I have one computer and one iPad I use for personal and business use. So I have multiple notebooks I use for personal use and business. All I'm saying is it would be nice to have a notebook not included in "All notes" so *if* I happened to have that view opened and someone was looking over my shoulder—even one of my kids—notes in that notebook wouldn't be included.
That's it. Sure, there are multi-step workarounds, but that's not how I (and I think many, many … many typical users) use Evernote.
This isn't about NSA encryption; this is about accidentally revealing a note I'd rather not have someone see at that moment. The password is a second level that seems like a logical extension, but it's less critical.