There's no camera in the TV. What they can do, though, is pick up the modulation on the electron beam that scans the TV screen to create the picture.
It's been years since I worked with classified computers, but back then the monitor had to be TEMPEST certified, because otherwise someone near the building could pick up what was on the screen, by detecting that modulation.
In England, where radio and TV sets have to be licensed, the "TV police" use to drive up and down the streets listening for the Local Oscillator of radios and TVs. They could tell if you were using an unlicensed set. Had they wanted to, they could have listened or watched what you were listening to or watching.
They can't see you, but they can tell what you're watching.
I don't know if this is still possible with TVs with plasma or LCD screens, nor with digital TVs.
There was some talk a couple years back, about spreading the CC device among the pixels of the screen in order to let you look directly at the person on the screen when teleconferencing, instead of looking at the top of the screen and looking retarded.