Is home privacy possible?

[AmethystxMoonstone]

Is it possible to make a room in a house/building private?  Meaning, if someone is behind the door (or further away even), they can't shift the camera view to "peek" through the wall?

All I can find are security systems that allow or eject persons onto land or a section of land.  I believe even a next door neighbor could zoom in to your bedroom if they wanted to.  Any way to prevent this?

[Qie Niangao]

Kinda. If you have the ability to create a separate parcel for the area you want to keep from prying eyes, you can then set the "parcel privacy" Option to disable "Avatars on other parcels can see and chat with avatars on this parcel" which means they won't be able to see anybody (nor anything anybody is sitting on) inside the parcel. No walls required.

Besides creating that parcel, this also requires that avatars who aren't supposed to see inside are not themselves inside the parcel. For that, there are parcel Access settings, as well as the scripted "security" measures you mention. Using parcel Access control (banlines) prevents immediate entry, rather than a script wasting resources sampling fast enough to remove an intruder with acceptable delay. There are however limits to the height of both the "parcel privacy" setting and the banlines, so skyboxes are kind of limited to the scripted "security" stuff. (I understand that avatars above the parcel privacy height are unable to see down below that height, although I've never tried it myself.)

[Nalates Urriah]

Privacy has different meanings. Privacy settings make it possible for avatars to be hidden. But, one can still cam through the area. They still won't be able to see an avatar. So, you can hide someone but not a 'something' from cameras flying through.

As Qie points out, you then have to set access. Otherwise one can walk into the parcel and see everything, avatar or thing.

In general, there isn't a lot of privacy in SL.