But when it is used as a political tool to harass or blackmail people, the consequences are different and corrosive. But the NSA and GCHQ aren't the only entities spying on webcams.
Marcus Thomas, a former assistant director of the FBI's Operational Technology Division in Quantico, Virginia, tells the Washington Post that the FBI could spy on anyone's webcam without turning on the camera's indicator light.
On top of this, his solution has gone around Android's notification that an APP is running, so you cannot even check to see if this brilliant piece of software "mal-engineering" is running.
Camera spying is so widespread that it's happening in schools.
All this happens without any awareness by the phone user -- the screen can either be turned off or on, it does not matter.