Well, my first reaction would be a whole mess of questions, as it raises a ton of legal issues...
1.) What is the definition of "book" for this statute?
2.) At what point do we begin to toll the age of the book? Is it from when it was first written, or when it was last printed?
3.) May a book which is banned under this statute still be protected by copyright laws?
4.) Do the standards for copyright apply to books that are banned? For example, under modern copyright law, I can't produce a work which is sufficiently like another work. Under this statute, could I simply make a line for line copy of the book "Lord of the Rings" and simply title it "Lord of the Bling", therefore making it a 'new' work (As the banned book no longer exists)?
Let's say the government was introducing a new law regulation banning books more than 50 years old.
How would you feel about this?
This quite literally would never happen in the US. Too many religious lawmakers in the US.
Still, even if it would happen it'd be a sad day, since failure to understand the past encourages one to be doomed to repeat it's mistakes. We have books which teach us things from back then that we'd have to re-discover. It's idiotic to remove them.
If you ban the bible it would be re-interpreted and re-published every 50 years. It would become Conservapedia's wet dream of re-imagining Jesus into a successful job creator and gun-toting hardline conservative.
And for all those that can't see it ever happening, have you READ Fahrenheit 451?
Even for those who did. Most people seem to miss the underlying plots.
Main plot: The government burns books to keep citizens under their thumb, oppressed, and uninformed so that they may be a fully controlling government body, free tax, arrest, start wars, and do whatever else they want as they see fit.
Sub Plot: This is what most people seem to miss. The government didn't just come in and take over with weapons and force. They people GAVE them the power to do this.
People were so busy in their computers/tvs/social lives/entertainment, always searching for instant gratification, that they didn't want to have to worry about all the problems of the world.
Friend 1"Oh did you hear about that fight that started between those two countries over seas? I don't remember what their names are....."
Friend 2 replies " Oh yeah! I don't remember either, but I think they are over on that side over there...well never mind it doesn't matter! Are you going to see that cool new movie tonight? There are supposed to be zombies and action and like 150 people get slaughtered onscreen!"
Friend 1" Hell yeah! That movie is supposed to be the shizz! If we get there we can get front row seats! The new tech at the theater is supposed to make you feel like your getting splashed with their blood!"
^ THIS was what led to the government controlling everything.
People were so busy trying to get what they wanted, that they didn't care about anything that didn't directly affect them anymore.
In the book, because books take so long to read, the language was parsed down into easy to remember phrases. This meant that after a series of years, Books became unnecessary, as all the information that a person could ever need was either condensed into shorthand (read chatspeak) or was stored on a devices that could call it up at any point in time.
But lets be honest. Who wants to read a book that makes you cry, when you can go sit in front of a TV and laugh at people making idiots of themselves? Why do you want to read about the horrible wars, and slaughters, and things that make people fight like religion, when you can sit in peaceful happiness in your home, oblivious to the pain?
In the end, the government removed the books because people didn't WANT them. Then by removing them, they made sure that the remaining people, the very small minority who did, no longer had access to information that could cause an uprising and make their oh so blissful citizens unhappy.
You may try to see that it will never happen. But do you have ANY idea how close we are to that occurring? Eventually the only books will be in museums because everything is on computer! Then when the government decides its time, they will be able to slowly delete them one by one, and no one will remember what books were there to start with. Then they destroy the remainder, and that's it. New generations don't know of our old mistakes, of a time when the government didn't rule everything, of a time when we had the freedom to make our own decisions. Every day we inch closer and closer to this as a reality.