Vs. Big Brother, where there is a top-down observer watching many, in Little Brother, everyone watches each other.
An alternate definition mentions that those who overshare are participating in, "The inverse of paranoia about the governing power or establishment collecting information about an individual. (See Big Brother) Those afflicted by little brother syndrome intentionally share and broadcast information about themselves via social networks, check-in websites, and GPS devices, often with little regard to personal privacy, or long-term consequences. Possibly a form of exhibitionism, this definition of Little Brother Syndrome may be related to, or even a consequence of another definition of Little Brother Syndrome wherein a person vies for attention to make up for feeling under-appreciated.
Grover apparently doesn't care who knows all about him, as he posted his home address, salary, and cell phone number to Twitter, Facebook, MySpace, and Wikipedia today. He's definitely suffering from Little Brother Syndrome"..