The major irony is that Winston thought that he could hide his journal, writing, thoughts, hatred of Big Brother, whatever, by hiding his activities and putting on the proper face at the "Two Minutes Hate." he irony is that, no matter how you hide your actions, you can't hide from the thougt police because they can read your rebellion in your face. Probably the best example of this is Mr. Charrington. Winston goes into his store and purchases trinkets and finally rents his room, always thinking that Charrington was unaware of what he was "up to" because he hide his intentions while Charringon knew quite well by reading his expression, much as Julia did, that he was rebel. The same is initially true of his relationship with O'Brien; although he misread O'Brien, Obrien had him pegged from the beginning.
Makes me wonder about all the pictures that are being taken of each of us every day ... are these a bad idea? They seem harmless in the possession of a benign government, but do I really want people in power knowing everything, or as much as they do now, about where I am and what I'm doing? And what if this government changes ... the information doesn't go away ....
"The price of freedom is eternal vigilance." [Thomas Jefferson]