Discuss the message conveyed by the Big Brother posters hanging in apartment buildings. How would this message differ if the posters only hung in public places?

I'm thinking that you mean the slogan "Big Brother is Watching You". This is rather terrifying, especially in private places. This means that there is no "ownlife". People are watched anytime. What is even more frightening is people do not know when or where they are being watched at any given moment. Public places have a more communal sense to them while private spaces are personally threatening.