Error 451 is the new Ray Bradbury-inspired HTTP code for online censorship

Error code 451 tells you when content you want to see is blocked due to "legal obstacles."

The web is full of cryptic status codes that your browser shows when it can’t connect to a website, such as 403 Forbidden or 404 Not Found. Now the Internet Engineering Steering Group is adding one more error code for your browser—but this time it will make it all too clear why you can’t see something.

The IESG recently approved status code 451 that tells visitors they can’t see the requested content due to “legal obstacles,” which usually means government censorship. Former Google engineer Tim Bray suggested code 451, inspired by Ray Bradbury’s dystopian novel Fahrenheit 451, back in 2012.

Status code 451 can be used by a website such as Facebook or Twitter, or by network intermediaries like a firewall or ISP. At first glance, 451 seems like a great idea to notify citizens in repressive countries if their government is blocking specific content. But those types of governments are also likely to prevent their citizens from even seeing that error code in the first place. Plus, if you live in a country where information is restricted you’re probably well aware of why you can’t see a certain site.

Democratic and semi-democratic countries are the more likely places where 451 will become useful. Take, for example, the U.K. government’s decision in 2012 to force ISPs to block torrent site The Pirate Bay. Instead of throwing up a 403 Forbidden code, ISPs could instead return 451 to make it clear why their customers can’t see specific content.

The U.K.’s decision to block The Pirate Bay and a blog post by Terence Eden by way of Slashdot is what inspired Bray to suggest 451.

Why this matters: As the web becomes even more central to our lives there could be all kinds of reasons for a site to be blocked. Perhaps a court will order a webpage with a 3D printing schematic blocked because it violates a patent, trademark, or copyright. A government body may decide to block more torrent or streaming sites, or perhaps the “right to be forgotten” in Europe will be expanded to affect specific webpages. Whatever the reason, in any country where there’s at least some freedom its citizens must know when their governments have restricted their ability to access information. Error code 451 scratches that itch.

[via Engadget]

Join the newsletter!

Or

Sign up to gain exclusive access to email subscriptions, event invitations, competitions, giveaways, and much more.

Membership is free, and your security and privacy remain protected. View our privacy policy before signing up.

Error: Please check your email address.
Keep up with the latest tech news, reviews and previews by subscribing to the Good Gear Guide newsletter.

Ian Paul

PC World (US online)
Show Comments

Essentials

Mobile

Exec

Budget

TerraCycle Zero Waste Box Pens and Markers Small

Learn more >

Back To Business Guide

Click for more ›

Brand Post

Most Popular Reviews

Latest Articles

Resources

PCW Evaluation Team

Christopher Low

Brother RJ-4230B

This small mobile printer is exactly what I need for invoicing and other jobs such as sending fellow tradesman details or step-by-step instructions that I can easily print off from my phone or the Web.

Aysha Strobbe

Microsoft Office 365/HP Spectre x360

Microsoft Office continues to make a student’s life that little bit easier by offering reliable, easy to use, time-saving functionality, while continuing to develop new features that further enhance what is already a formidable collection of applications

Michael Hargreaves

Microsoft Office 365/Dell XPS 15 2-in-1

I’d recommend a Dell XPS 15 2-in-1 and the new Windows 10 to anyone who needs to get serious work done (before you kick back on your couch with your favourite Netflix show.)

Maryellen Rose George

Brother PT-P750W

It’s useful for office tasks as well as pragmatic labelling of equipment and storage – just don’t get too excited and label everything in sight!

Cathy Giles

Brother MFC-L8900CDW

The Brother MFC-L8900CDW is an absolute stand out. I struggle to fault it.

Luke Hill

MSI GT75 TITAN

I need power and lots of it. As a Front End Web developer anything less just won’t cut it which is why the MSI GT75 is an outstanding laptop for me. It’s a sleek and futuristic looking, high quality, beast that has a touch of sci-fi flare about it.

Featured Content

Don’t have an account? Sign up here

Don't have an account? Sign up now

Forgot password?