I agree with what people are saying in regards to having an added feature such as a simple checkbox which would allow us to password protect specific libraries even though we already have the ability to set up individual users with individual pin codes. That second layer of authentication or “two-factor authentication” would be more of a peace of mind and probably not that difficult implement. I say that because I own an IT & application development company and there are much more complex features already within Plex.
What I’m about to explain I’m sure a good majority of Plex users know about and utilize already so I apologize to those seasoned Plex users for explaining the features my family uses in simplistic detail…I imagine it could be a boring read. On the other hand, I hope it helps shed some light on the power we already posess inside Plex as it currently stands.
I have thousands of movies and tv shows on my Plex server and have been using the application for many years now. I have 4 children, 3 boys and a girl ages 9, 7, 4 & 1. I have several user accounts to control content ratings, one for each of my family members and an administrative account which I use for adding categories and performing updates, along with other maintenance-related tasks. My wife and my account each have 4 digit pin codes which allow us to have a more “tailored” feel to the experience…for instance my wife and I obviously like different shows and I do not want her “On Deck” Vampire Diaries on my interface LOL … while at the same time she would rather not see my “How the Universe Works” space stuff. It allows us to keep track of what we’re watching, resume, etc. and works outstandingly. My kids each have their own accounts, yes even my 1 yo daughter, because her older brothers would rather not have “Baby Einstein” popping up. Furthermore, each account allows for custom tailored libraries and even more granularity within each of those. Each user account maintains the same theme by allowing the admin to configure very specific permissions such as only allowing specific genre, MPAA ratings, etc. Unfortunately, I have found the user settings to flag specific genre and MPAA ratings severely lacking in consistency because the Plex scanner does not work well at all to properly categorize our entire library despite the fact that all of our media is named correctly, recognized by each of the various “mainstream” agents and categorized properly. To correct the inconsistency I have created separate folders called “animated kid flix” or “kids tv” as well as “kids movies” or “PG-13” for my older son, “bluray”, “tv shows”, etc. Each of these folders I make into a Library and from there I use the individual user accounts to flag what categories are appropriate and accessible by each user. It works well and is an easy to implement one-time configuration because let’s face it, how many different media libraries would someone really need and how often would they need to be changed? As such, we also have family photos and videos I can categorize similarly so the kids do not have access to, for instance, my wife and my honeymoon photos
preventing access to our personal & sometimes very private media from anyone other than us. In addition to that, since we still have the ability to flag individual Libraries for access within each user account we remain able to allow our kids to have access to all of the photos and videos which are uploaded from our family events, trips and each of their individual tablets or phones. One thing I have not done which I have had on my to-do list for some time, in regards to family videos and pictures, is to give my extended family access to those Libraries allowing our loved ones and friends access to our memories without having to upload everything to social media. There’s nothing happier than a grandparent who has realtime, on-demand access to their grandchildren 
On a separate yet similar note, setting the kids devices to auto upload photos & videos from their tablets & phones give my wife and I another way of monitoring what they’re doing when we’re not around because it’s all synchronized automatically Taking into consideration the unrestricted, mostly unfiltered and unbridled access most children & young adults have on the Internet now, monitoring what they’re watching as well as taking pictures or videos of is an unquestionable necessity.
Again, I do believe there should be some sort of “two-factor” second layer of security in case a child for someone who should not have access to a specific library somehow gains access to the library. If that happened they would be asked a second pin code (hopefully different) in order to move further or any deeper into that user’s libraries. I would also suggest having the ability to encryption on specific media on the disk drive at rest and in transit to ensure the data is not compromised further … that may seem a bit over the top but my company specialized in cyber security, cyber terrorism, and data protection as well as recovery so to me it’s a no-brainer.
In the end, having a second layer of protection would put many minds at ease knowing that redundancy is in place just in case we accidentally leave our account up on an Xbox, DVR, or a phone or tablet. I would really like to see Plex implement this feature in the near future.
Thanks for reading if you made it to the end of this post. Hopefully I clarified or helped someone with the book I just wrote. Haha…
J Burgess
aka Tripaphonic