At the bottom of the page, "Thanks also to Ray Bradbury."

It appears they deliberately chose 451 in homage to the great Fahrenheit 451 (or more specifically, to the dystopian future presented in the book).[1]

[1] http://www.techdirt.com/articles/20120725/06093819827/truth-...

Fahrenheit 451 isn't about censorship, though. People often mistake it as a book against censorship, but in reality it's a book against television.

You can read more about it here http://www.laweekly.com/2007-05-31/news/ray-bradbury-fahrenh... and listen to bradbury (quicktime required, sorry) here http://www.raybradbury.com/at_home_clips.html

Edit: Also, paper burns at 451 degrees Celsius, not Fahrenheit.

> censorship

You're interpretation is disingenuous. Yes, the larger story is about the decay of intellect in society. However, it's a forced conversion, so that's where the censorship comes into play.

> 451 degrees Celsius

Your source is an extreme outlier.

So, when will they start burning urls?

The job now falls to the Writermen. They excerpt, rewrite & aggressively-SEO... so that no original, true, or subversive ideas ever rank in top 450 search results (unless wrapped in neutralizing snark).

It's "SearchRank-451".

they do it at the firewall...

They're hard to set alight.

the word is dystopian

This reminds me very much of the TCP Evil Bit [1]. That is, it seems like the issue of whether anybody would actually set this is essential to the question of whether or not it would work.

One could even imagine that governments would want people to live in ignorance of the existence of restrictions. It's 100% the Ethan Zuckerman Cute Cat Theory of Internet Censorship [2]. The government would rather that you have all of YouTube except the subversive content, because then you might not notice the restriction and so will learn not to care.

Indeed, from the document:

  "The use of the 451 status code implies neither the
  existence nor non-existence of the resource named in the
  request.  That is to say, it is possible that if the legal
  demands were removed, a request for the resource still
  might not succeed."

That suggests to me that the author is also aware of this problem.

It should be noted that Google has done an amazing job in trying to fix this problem by trying to force whole services to be blocked when that's feasible and by transparently explaining (in the UI itself!) when content is unavailable for legal reasons. Kudos to them.

For that reason, I would say such an effort is worthwhile even if it won't have much impact: it's quite likely that it will help further the norm that when censorship exists it should exist transparently. That's a cause worth fighting for, even if every step is going to be a huge challenge.

[1] http://www.ietf.org/rfc/rfc3514.txt

[2] http://www.ethanzuckerman.com/blog/2008/03/08/the-cute-cat-t...

People will set this to indicate that they had to censor something. Obviously if you don't want the censorship to be detected, you will not use this code.

The FBI replaces websites it takes down with a graphic containing their logo, they might use the 451 code if it becomes standardized.

"This request may not be serviced in the Roman Province of Judea due to the Lex Julia Majestatis, which disallows access to resources hosted on servers deemed to be operated by the People's Front of Judea."

Ave Caesar, moritURI te salutant

Discussion from last year: https://news.ycombinator.com/item?id=4099751

Already used by LiveJournal in Russia:

Example: http://drugoi.livejournal.com/3712998.html (slightly NSFW) — if you visit this URL from Russian IP address, you'll see something like this: https://www.evernote.com/shard/s72/sh/6e76310b-daec-454c-a66...

Allegedly, this page and photos are used to propagandize suicide.

Warning, the link contains pictures of a man on fire.

I think if these types of messages were as jarring as possible instead discreetly displayed in the existing interface it would heighten people's awareness of these issues.

I have mixed feelings about that. On the one hand, you're right that people should be made distinctly aware when something is being censored. On the other hand, you have to be careful not to convey the sense that the user is in the wrong or frighten anyone into self-censorship by giving the impression that the user could be sold out to an oppressive regime by the service provider.

There's no reason a site couldn't serve content along with the 451 code, just as HTTP200 is served with content.

In fact, that's a SHOULD in the RFC:

    Responses using this status code SHOULD include an explanation, in
   the response body, of the details of the legal demand: the party
   making it, the applicable legislation or regulation, and what classes
   of person and resource it applies to.

Or how HTTP 404 is served with content.... (e.g. http://github.com/xyzzyeieio - there's a good 134KB text/html with your 404 error code)

This perhaps would top HTTP Response Code 418 "I'm a teapot"

http://tools.ietf.org/html/rfc2324

Mozilla is apparently using this in their AMO/Marketplace codebase:

http://firefox-marketplace-api.readthedocs.org/en/latest/top...

The most startling clause is this:

   The 451 status code is optional; clients cannot rely upon its use.
   It is possible that certain legal authorities may wish to avoid
   transparency, and not only demand the restriction of access to
   certain resources, but also avoid disclosing that the demand was
   made.

It seems this clause, as highlighted by deepblueocean in his "TCP Evil Bit" comment, is what is most disturbing... Shouldn't it be made mandatory? Can it be made mandatory?

China: "451 all the things"

The GFW generally works on the TCP layer, resetting the session which delivers some sensitive-keyword-containing payloads, both in and out of the boundary.

Damn it, not more HTTP status codes, I want 402 to work all ready!

The draft was published on Jan 11. Why is it relevant, today?

I prefer my internet without legal interference.