New HTTP error code 451 to signal censorship After a three-year campaign, the IETF has cleared the way for a new HTTP status code to reflect online censorship. The new code – 451 – is in honor of Ray Bradbury's classic novel Fahrenheit 451 in which books are banned and any found are burned. The idea is that rather than a web server, proxy or some other system returning …
Does Paper Really Burn at 451 Degrees Fahrenheit?
Several Internet contrarians claim that Bradbury confused Celsius and Fahrenheit, putting his estimate off by 391 Fahrenheit degrees. They cite as evidence the Handbook of Physical Testing of Paper, which lists paper’s ignition temperature as 450 degrees Celsius. (Wikipedia cites the same source.) It’s not entirely clear how this number was arrived at, but it is an extreme outlier. The author appears to have used paper made with rayon or cotton, which could have a different auto-ignition temperature from pure wood pulp paper, but 450 degrees Celsius still sounds wrong. It’s also possible that the experimenters didn’t wait long enough or that they (and not Bradbury) switched Celsius and Fahrenheit.
It appears that the Centigrade / Fahrenheit being swapped story is not true, although most experts set the figure at around the 470 - 480 F mark, depending on the type of paper and environmental factors.
451 C is about the auto-ignition temperature for metals like magnesium.
The BigBrother monitoring software used port 1984, which tickled me.
Personally hoping for widespread adoption of 451 code in 2016 followed by a push in 2017 to challenge each instance that causes it to pop up. But perhaps I'm getting optimistic in my dotage.
Yeah and "418 - I'm a Teapot" was such a great use... Besides, would this already be covered under a couple other codes? Error 403 springs to mind or even 410.
But that ignores the fact that most censorship is going to happen on the wire anyway, so either error 404 or a connection timeout would result. For most currently censored things, the protocol seems to be to use a redirect to a page describing why and who is censoring the data, something much more helpful than a cryptic error code.
"But what the browser do?"
Automatically attempt to fetch the file from google cache, archive.org, via Tor, and using an alternate DNS server. Or, if the query is an IMS, mark the version in the cache as 'does not expire, ever, do not IMS.'
The point of not returning an existing code is that some Web 2.0 sites, such as Wikipedia, have been edited to remove "dead" links that weren't dead at all, just censored in the editor's location. 451 means Wikipedia et al. can have a policy regarding when to leave such links in place.
An automated response by the browser - sure, but only when the server or ISP tells it "Error 451".
So basically, it's just relaying a message from the web server (or, just possibly, from one of the ISPs sitting between you and the website owner). As such, it's basically a political message, and about as meaningful as any other political message you can derive from a website.
Yeah and "418 - I'm a Teapot" was such a great use
I have used it in a commercial product prototype for the rest interface as a generic error code which means "I have no clue what I should do" (a fairly common situation in a provisioning system - modeling failures, unspecified comms failures across a gateway interface).
The fact that it is not used in browsers is not an indication that it is not used.
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Wonkypaedia suggests that this status code is already used by Microsoft.
"451 Redirect (Microsoft)
Used in Exchange ActiveSync if there either is a more efficient server to use or the server cannot access the users' mailbox.[68]
The client is supposed to re-run the HTTP Autodiscovery protocol to find a better suited server.[69]"
So interesting times if this part of Exchange is ever exposed to web crawlers.
To be used by any server that is serving up goat.se or donkey porn (ass porn is usually fine), or sleb news or Twitter pages or Facebook or the mail online, or any Christmas ad ('go argosssss' - I mean, wtf is wrong with her?), any Apple ad since that Super Bowl one, or any 'get the facts' campaigns, or bloody runway expansion, or '10 weird old tips you didn't know about...', or pages of manufactured and pointless outrage, or whinging blogs written by self-centred egocentric immature morons who SHOULD GROW UP NOW, anything mentioning 'the cloud', or anything connected at all, no matter how obliquely, with Microsoft. That should do it.
Not necessarily, the client may have erred by being geographically located somewhere the content is censored.
But, actually, it's not a server error anyway. The client has erred by either requesting content that isn't available (404) or content the client isn't authorised to request (403).
The 5xx range is for where an action the server needs to complete has failed (upstream unreachable, parse error on a cgi script etc).
4xx is definitely the right range for this use, though it's applicability does seem a little limited. You'd use it if you've received a takedown, but an on the wire censorship mechanism is unlikely to use it
I could see using this in Academic circles, more precisely in Open Access Research Repositories where an article can't be publicly shared (possibly for a set time period) due to a publisher-imposed restriction. Then the research aggregation systems would discover why the item they are requesting is not available (possibly with a 'try-again yyyy-mm-dd' message in the description), rather than a generic forbidden message or a 200 response with a human readable page explaining that the item is not available.
Including a tryagain date in the status code isn't the best way of doing it, status code descriptions should be (relatively) static.
But adding a x-will-be-available-at or the like would be a nice touch, especially if people stick to the same header (much the same way as x-forwarded-for became defacto).
It could also be nice, for dmca type takedowns, to have a "standard" x-see-more containing a link to chilling effects or similar
"Don't expect to see 451 codes pop up in countries that routinely censor the internet, however. Typically those countries are not overly keen on letting their citizens know just how much information they are hiding from them."
So what will be the new code to let us know the error code has been censored? And then the one to say that the censorship of the censor code has itself been censored. Who censors the censors?
You certainly must mean "quis censebit ipsos censores" (or, if there is only one censor to watch, "ipsum censorem"), though this would still be dubious from a semantic point of view, since, while "censor" is certainly ethymologically related to "censere", the basic meaning of the verb is more along the lines of "to think (right)", "to believe" etc., as in "ceterum censo internautam non esse super grammaticos" and I'm not sure if "censorem censere" makes any sense at all (I don't have a copy of OLD at hand right now) but anyway this is now starting to get OT...
Say you are trying to stream latest online release from Disney studios while in Iceland. But, Iceland is not scheduled to receive it for another six months. It sounds like a legal reason for the content to be blocked and the 451 error would seem to apply. Then you know to use appropriate VPN to stream desired entertainment.
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