Big brother

an elder brother.
(sometimes initial capital letters) a man who individually or as a member of an organized group undertakes to sponsor or assist a boy in need of help or guidance.
(usually initial capital letters) the head of a totalitarian regime that keeps its citizens under close surveillance.
(usually initial capital letters) the aggregate of officials and policy makers of a powerful and pervasive state.
Citizens Band Radio Slang. a police officer or police car.
Contemporary Examples

Elephant Calf Lily Rescued by Oregon Zoo Winston Ross February 11, 2013
Our Favorite Books of 2012: Tina Brown, Andrew Sullivan, and Others’ Picks The Daily Beast December 10, 2012
First Day Out of Prison John Forté January 25, 2009
One Redneck’s Gun Stand Joe McLean February 12, 2013
My Friend, Roger Ebert: Pulitzer Prize Winner Tom Shales on the Moving Documentary ‘Life Itself’ Tom Shales July 5, 2014

Historical Examples

The Story of Patsy Kate Douglas Smith Wiggin
A Son Of The Sun Jack London
The Rover Boys on Treasure Isle Edward Stratemeyer (AKA Arthur M. Winfield)
David Elginbrod George MacDonald
New York Times Current History: The European War, Vol. 8, Pt. 2, No. 1, July 1918 Various

noun
a person, organization, etc, that exercises total dictatorial control
a television gameshow format in which a small number of people living in accommodation sealed off from the outside world are constantly monitored by TV cameras. Viewers vote each week to expel a person from the group until there is only one person left, who wins a cash prize

The faceless and ruthless power of the totalitarian or ureaucrati state personified (1949+)
The tracking radar used by ground controllers (1970s+ Airline)