The Purge takes an interesting concept - for one night per year, anything and everything (including murder) is legal - and then fails to deliver. The protagonist, a husband and father of two who lives in an upscale community, made a fortune selling security systems that aren't all that secure and gained the envy of his neighbors in the process. The film is clearly aimed at conservatives (the government is referred to as the "new Founding Fathers," the purpose of The Purge is to eliminate the poor, homeless and other "unproductive" citizens, and one wave of invaders are cookie-cutter Young Republicans)...
All Your Base are about to Belong To Us.
...but the envious neighbors who want to kill them for no other reason than that they're richer than they are takes a stab at Occupy-movement class envy as well. The entire movie is basically an ad for the NRA - our hero, for a security specialist, is rather poorly armed - and a textbook on how not to defend your home.
Brought knifes to a gun fight.
In the event of Purge or Zombie Apocalypse or whatever will befall us Southern Man's home defense will include remote-controlled claymores and gunports (in the film invaders are free to wander about the property at will, including cutting the power, standing on the front porch to threaten the occupants, and pulling the defensive screens off the windows with trucks and chains) and a rack of AR-15s. Indeed the entire "home defense" system in the film follows rather closely to Southern Sister's philosophy of passive resistance (and in Real Life Southern Man would love to put an 8' iron fence all the way around The Land). But it was a lot of fun to watch and raised a number of interesting questions.