While the LED light turns off when deactivated through the linked application, researchers have discovered that Google's Nest Cam doesn't fully deactivate, stating that it continues to function in a lower power state.
Expanding on these findings, The BBC says that the tested device "continued to draw a current of 340 mA" even when switched completely off, compared to a draw of 370 mA when turned on and operational.
While this draws concerns of 'Big Brother' Google or hackers being able to watch you at any time, Nest released a statement claiming that "when Nest Cam is turned off from the user interface (UI), it does not fully power down, as we expect the camera to be turned on again at any point in time." Further reassuring customers, they also said "when Nest Cam is turned off, it completely stops transmitting video to the cloud, meaning it no longer observes its surroundings."
To further protect your privacy, a Nest Labs employee also stated that these devices contain "128-bit secure sockets layer (SSL) encryption, perfect forward secrecy and a 2,048-bit RSA key unique to each camera."