Thanks for the reply BurgersNFries. Maybe it would become a priority if it was a small amount of extra money... I'd pay an extra $5/yr to be able to mark a notebook as encrypted. It's OK if that encrypted data is not indexed... It can be made understood to users that anything in the encrypted notebooks will not show up in search results. I would sit down and:
1. Tally up the number of Evernote premium subscribers.
2. Conservatively estimate the amount of development time, as well as time for updating help documentation, entering the extra password in the mobile apps, etc.
3. Run