Questions for the experts pls...

I am in Canada, our private screening areas are just behind a baffle, which is fine with me. Are the US ones actually behind a closed door in a room, or also behind a baffle/in a cubicle?

Also, if it is in a private sectioned off room where you can't see your belongings, what can you do to ensure you can keep an eye on your valuables during the screening so they don't get mistakenly taken. Do you just ask?

I'm flying out of Newark.