It's The Purge and you ain't killin no one.

Quick! The Purge has commenced, what are you going to do??
Your ass is going to stay home like almost everyone else and shoot anyone who wonders on your lawn, which will be no one...and here's why.

1.) Criminals would not be able to surprise their victims:
So if you are reading this it's obvious to me you're no criminal!  Crimes are possible because the criminals usually have the element of surprise. It's quite a bit harder to attack someone who is expecting it. Seriously, you guys do know that the United States still has more gun stores then any other country in the world. Let that sink in.. People would stock up on guns and weapons. There might even be red (lol) Friday purge sales. You know those crazy folks on Doomsday Preparers, those end is coming guys, or people who live in Kentucky? That would pretty much be everyone.
Public places (banks, stores, museums, ect)  would be locked up tighter than Fort Knox and probably have armed guards inside. Anyone with a bit of cash wouldn’t even stay in the country. Hey honey, The Purge is coming, lets vacay in Jamaica. Retired military men would start businesses training private citizens for the coming purge and how to survive. Poor and live in a bad neighborhood? They would still be armed and would most likely have traps and home made weapons that would possibly be even more dangerous than store bought weapons, if they didn't leave the cities completely.

 2. Your targets are saying, go ahead make my day... 
Murder is legal, you make the mistake of trying to screw with someone and they will shoot you in the head, over and over. Most criminals would be killed before they even got close to breaking into, well, anything. Crime would probably be lower that night. Actually this is the only way the Purge would lower crime, by making criminals incapable of committing crimes because if they do..they will get blown away.

3. You kill someones loved ones and your probably going to get it next year.
(or sooner) Oh your just going to pick on the poor and homeless, no one saw you and your all good. (already explained why you wouldn't be able to do that but ok..I'll go with you here) Well great you're admitting you are a complete sociopath. Glad you have identified yourself so we can lock you away in Arkham Asylum since there isn't really going to BE a purge..but I digress. I mean your sociopathy is cool and all but even homeless sometimes have friends and loved ones, and if you ARE found out, you're a dead man walking. Is it worth it??

4. You, for no reason just turned into a killing machine? Ok then.
There’s no way a normal, well-balanced individual can go out and just kill people out of the blue. You don't just become a sociopath one night a year. Plus the idea that acting out aggression leads to emotional relief is mostly false. The reality is that acting out rage is more likely to increase aggression AND it would reduce guilt making most people MORE likely to commit crimes year round.

5. So the Purge seems like a way for the rich to control the poor
In the first chapter of The Purge it seemed like a bunch of jerky rich people hurting the poor. (or each other) Let me follow this line of thought. (Ok, Lets say the poor are just completely without resources to do anything to protect themselves, which really isn't a reality anyway..but lets go here) 
Reality check, After a few years of the Purge, the poor would preemptively fight back. There would be a revolution. Even now, people will only take so much crap before they are just no longer willing to do so. Eventually the streets would run turn red with the decapitated heads of prep school rich kids and employers who treated their staff like crap, and the poor wouldn't wait for the actual purge.

6. So what does all this mean?
CNN is going home. What would happen?? Well...almost nothing. (domestic disputes, eh- Maaaybeee)  Most criminals know how to be criminals or they wouldn't be criminals..they would be in jail...and going after an armed target that is expecting you isn't a good idea. Only crazy or stupid people would go out and actually carry out their plans, and they would find their targets waiting.

7.) So I still can't wait to see the movie...
Seriously, it's going to be epic. :)