The Village, where Number 6 is imprisoned, never achieves full concreteness throughout the series. We never find out who the Warders are, what they want to know, why they want to know it. Very few Prisoners are revealed to us in any particularity. This is all left vague. This is Number 6's predicament, too, so we remain on par with him and are meant to share this point of view.
Number 6 tries to escape the Village and its island throughout the series. He fails until the end, when he unravels the Village from the inside. Number 1, it turns out, has the visage of Number 6 and has been, perhaps, Number 6 all along.
Why has Number 6 been trapped if he is Number 1? The answer is likely that Number 1 is a placeholder and not a person; a placeholder for the idea of progress which, alas, has come to be equated with surveillance and control.
Like Number 6, we come to understand that one cannot escape the Village physically. This is not because of the technology of the village, which is ubiquitous and seemingly omnipotent; rather, physical escape is impossible because freedom, and its tools (such as surveillance) are internal attitudes.
Questions about the individual's attitude toward their own freedom (and their complicity in their internalization of others' control) are part of the show's dialogue from the very first episodes. But it only becomes catalytic of change once Number 6 fully realizes that the crucial dimension of control is internal. Only then can he effectively attack the Village's own logic and drive it into absurdity and dissolution.