Earlier quoted context omitted.
The 4K Chromecast "with Google TV" basically was that already, since it has the full-screen menu-based interface and remote. It seems a bit silly to me that they're tossing the brand aside but maybe they're doing that for exactly this reason.
I have one of these and I am going to be blunt: I just can't figure out the privacy. At. All. I have kids (and their many friends) running through the house using TVs and streaming etc and I don't want them browsing through my YouTube viewing history or filling it up with their dumb kid shows nor accessing things I don't think are appropriate at random times. But for whatever reason when I plug in the 4K with Google…
The latest one in my bunch has a remote and menus and stuff, and is what I presume y'all are talking about. I've seen it referred to as CCWGTV.
"Privacy" seems easy-enough and is not so dissimilar to "privacy" on any other shared computer: Just set up profiles. One for you, one or more for kids, one for guests, or whatever makes sense.
For your own profile, set a PIN. (The included d-pad remote makes PIN entry easy-enough.)
Aaaand... done?
Mine also does old-school phone-driven Chromecast stuff just fine with zero profiles logged in -- while it is just sitting there at the profile-select screen. In this mode, it accepts Youtube and Spotify and whatever else I throw at it.
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Am I doing something wrong?