Page "Telescreen" Paragraph 2

O ' Brien claims that he, as a member of the Inner Party, can turn off the telescreen ( although etiquette dictates only for half an hour at a time ).

It is possible that this was false and the screen still functioned as a surveillance device, as after Winston and Julia are taken into the Ministry of Love, their conversation with the telescreen " off " is played back to Winston.

The screens are monitored by the Thought Police.

However, it is never made explicitly clear how many screens are monitored at once, or what the precise criteria ( if any ) for monitoring a given screen are ( although we do see that during an exercise program that Winston takes part in every morning, the instructor can see him, meaning telescreens are possibly a variant of videophones ); Telescreens do not have night vision technology, thus, they cannot surveil in the dark ; this is compensated by the fact that telescreens are incredibly sensitive, and can pick up a heartbeat.

As Winston describes, "... even a back can be revealing ..."