Category-level security controls would solve many common use cases. Sharegroups, password-protected galleries, site-wide passwords, and unlisted galleries all come with their own set of problems and limitations. I wrote a skeleton proposal for a more cohesive security and privacy implementation that also includes category-level security controls, along with a simple but more relevant authorization scheme. You can check it out here:
Below, I'm re-posting some of the problems I noted with the current offering of security and privacy controls. My suggestion above attempts to address these and make the Smugmug Homepage and site more capable of displaying both a Public and a Private face.
1) Unlisted galleries are a good idea, but they blow the whole Categorical structure. If I have private content I now need to send someone a link, which they'll likely loose in time. I can't send them a private 'Family' category link, and let them browse all of my private family content. But then there's...
2) Sharegroups, which almost solve the above problem, but come with their own. For one they only allow galleries to be added, and since I cannot put a Category in a Sharegroup, I cannot simply say - okay here's all my Family stuff, with all of its subcategories and galleries, and one unlisted link to all of it. On top of that, the entries are static, so I have to manually add galleries as they become available.
3) Site-wide passwords. We all know passwords blow, last thing we want is yet another password to forget. Site-wide passwords are almost cool, except they blow the whole concept of a Homepage, so then, there's no way for me to display any of my public stuff to the anonymous visitor... Or maybe I just want a couple smart galleries to display on my Homepage to people who don't have the site-wide password.
4) Then there's gallery-passwords. So I could just put a password on all my private galleries, and not put one on my public galleries. That might work! But wait, then my Homepage, which I'd like to include Gallery Categories on, would even let people without the passwords browse the whole structure, see all my gallery names, maybe even find some information I didn't want them to see! So now I guess it's back to unlisted galleries and sharegroups again, and back to square 1.
It's a bit maddening. There currently seems to be no easy way to display separate Public and Private views on the Homepage in a way that offers the following: