That's actually a good addition, I haven't seen the film as of yet but know enough about it to make the call. Thanks!
May I suggest The Cube. Massive building that hs rooms that move around in a seemingly random way, created by many disparate groups for no particular reason, other than because they can? Then kidnap a group of people drop them in the middle and....well you know the rest. But definitely a metaphor for urban isolationism wouldn't you think?
Suggestion (and I can't think of a better one than this): Vive L'Amour. Urban Isolationism at its best.