Proposal To Establish HTTP Status Code 451 For Websites Blocked By Censorship

By Darren Smith, Weekend Contributor

ietf-logoWith the increasing frequency of government censorship and take-down orders blocking content hosted on web servers, a consortium of internet stakeholders has proposed to the IETF an RFC Draft (recently published) proposing a standard error response given to clients that the web page or resource sought has been blocked for legal reasons.

The proposal uses the status code 451, a reference to Ray Bradbury’s book “Fahrenheit 451”.


Most users have seen the familiar “404 Not Found” or “403 Forbidden” error messages when accessing a page that does not exist or one that has restricted access. Under the surface these HTTP (HyperText Transfer Protocol) tags regulate client and server transactions, such as page request, authentication required, OK statuses and numerous others handled by the web browser and the website it is connecting to.

A pertinent excerpt from the draft before the IETF reads as follows:


This document specifies a Hypertext Transfer Protocol (HTTP) status
code for use when a server operator has received a legal demand to
deny access to a resource or to a set of resources which includes the
requested resource.

This status code can be used to provide transparency in circumstances
where issues of law or public policy affect server operations. This
transparency may be beneficial both to these operators and to end

[RFC4924] discusses the forces working against transparent operation
of the Internet; these clearly include legal interventions to
restrict access to content. As that document notes, and as Section 4
of [RFC4084] states, such restrictions should be made explicit.

451 Unavailable For Legal Reasons

This status code indicates that the server is denying access to the
resource as a consequence of a legal demand.

The server in question might not be an origin server. This type of
legal demand typically most directly affects the operations of ISPs
and search engines.

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. For example:

HTTP/1.1 451 Unavailable For Legal Reasons
Link: ; rel=”blocked-by”
Content-Type: text/html

Unavailable For Legal Reasons

<h1>Unavailable For Legal Reasons </h1>
<p>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.</p>

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.

Note that in many cases clients can still access the denied resource
by using technical countermeasures such as a VPN or the Tor network.

A 451 response is cacheable by default; i.e., unless otherwise
indicated by the method definition or explicit cache controls; see

The 451 Error Code is an improvement from the present use of 403 Forbidden or in many cases 404 Not Found because among other things it informs the user that a particular resource has been blocked for legal reasons, and gives the opportunity to explain why. Typically the information “just disappears” and returns as a 404 when requested.

Discussion was made as to why 403 Forbidden would not suffice. There are reasons for which a server will return such a request due to technical reasons, such as Directly Listing Prohibited which often displays itself when directory read permissions are not granted to unauthenticated users and an index.html or default.asp file is not provided to service the request. So in a sense 403 errors are not really suitable for human abstracts such as censorship.

It is apparent, unfortunately, that unscrupulous governments in the world will demand content be removed without notice and will view the 451 response as a latency of the original censored resource, and consequently disallowing the use of 451 error codes.  It can be used in other contexts where a resource was taken down due to the author being served a take-down notice for copyright violations, etc.

Intermediaries such as content hosting sites like social media providers can easily use this. If the content is prohibited by law, such as access to Nazi paraphernalia sold on eBay which is blocked in Germany (Which of course is another matter in of itself) the 451 can be returned to users geolocated within that country but for everyone else the page will pass through.  This at least will inform the user what happened.

Another feature would be to allow the automated spidering and indexing of the web to identify the scope of censorship and track trends and growth of the practice.

It is however disappointing that such a measure needing to be addressed with regard to content censorship becoming such a norm that an RFC needs to be made to address the problem.  Twenty years ago I never would have expected this to become the new reality.

By Darren Smith


The Internet Engineering Task Force

The views expressed in this posting are the author’s alone and not those of the blog, the host, or other weekend bloggers. As an open forum, weekend bloggers post independently without pre-approval or review. Content and any displays or art are solely their decision and responsibility.

38 thoughts on “Proposal To Establish HTTP Status Code 451 For Websites Blocked By Censorship”

  1. I’m afraid that as with almost all social policy, the government will find a way to turn it against the majority. I like the 451 proposal but how would we enforce it? It seems to me the only ones that would end up doing any enforcement are the ones I’m skeptical of.

  2. I think citizens should have the right to own firearms which would match those used by the gov’t if at sometime we have a need to overthrow some tyranny. When the Redcoats are coming I want to have a level playing field. The right to bear arms goes beyond defense of home.

  3. The above article is a bit long. But as one who was in The South about 40 years ago and witnessed the Klan coming around with automatic weapons provided for free by the COINTEL Program, I thought you should know something about the other side of this government propaganda.

    You have the right to bear arms. Or arm bears.

  4. Sort of On Topic on this lame topic: the insurrection out West by the Bundys. The dialogue on media networks is about the nuts. They want you all to think that you have no need for weapons. They want you to forget our history. Here is some history of the FBI Cointel Program:



    Centralized operations under COINTELPRO officially began in August 1956 with a program designed to “increase factionalism, cause disruption and win defections” inside the Communist Party U.S.A. (CPUSA). Tactics included anonymous phone calls, IRS audits, and the creation of documents that would divide American communists internally.[9] An October 1956 memo from Hoover reclassified the FBI’s ongoing surveillance of black leaders, including it within COINTELPRO, with the justification that the movement was infiltrated by communists.[10] In 1956, Hoover sent an open letter denouncing Dr. T.R.M. Howard, a civil rights leader, surgeon, and wealthy entrepreneur in Mississippi who had criticized FBI inaction in solving recent murders of George W. Lee, Emmett Till, and other blacks in the South.[11] When the Southern Christian Leadership Conference (SCLC) was founded in 1957, the FBI began to monitor and target the group almost immediately, focusing particularly on Bayard Rustin, Stanley Levison, and, eventually, Rev. Martin Luther King, Jr.[12]
    The so-called “suicide letter”,[13] that the FBI mailed anonymously to Martin Luther King, Jr. , in an attempt to convince him to commit suicide

    After the 1963 March on Washington for Jobs and Freedom, Hoover singled out King as a major target for COINTELPRO. Under pressure from Hoover to focus on King, Sullivan wrote:

    In the light of King’s powerful demagogic speech. … We must mark him now, if we have not done so before, as the most dangerous Negro of the future in this nation from the standpoint of communism, the Negro, and national security.[14]

    Soon after, the FBI was systematically bugging King’s home and his hotel rooms.[15]

    In the mid-1960s, King began publicly criticizing the Bureau for giving insufficient attention to the use of terrorism by white supremacists. Hoover responded by publicly calling King the most “notorious liar” in the United States.[16] In his 1991 memoir, Washington Post journalist Carl Rowan asserted that the FBI had sent at least one anonymous letter to King encouraging him to commit suicide.[17] Historian Taylor Branch documents an anonymous November 21, 1964 “suicide package” sent by the FBI that contained audio recordings of King’s sexual indiscretions combined with a letter telling him “There is only one way out for you. You better take it before your filthy, abnormal, fraudulent self is bared to the nation.”[18]

    During the same period the program also targeted Malcolm X. While an FBI spokesman has denied that the FBI was “directly” involved in Malcolm’s murder, it is documented that the Bureau worked to “widen the rift” between Malcolm and Elijah Muhammad that led to Malcolm’s assassination.[19][20] The FBI heavily infiltrated Malcolm’s Organization of Afro-American Unity in the final months of his life. The Pulitzer Prize-winning biography of Malcolm X by Manning Marable asserts that most of the men who plotted Malcolm’s assassination were never apprehended and that the full extent of the FBI’s involvement in his death cannot be known.[21][22]

    Amidst the urban unrest of July–August 1967, the FBI began “COINTELPRO–BLACK HATE”, which focused on King and the SCLC as well as the Student Nonviolent Coordinating Committee (SNCC), the Revolutionary Action Movement (RAM), the Deacons for Defense and Justice, Congress of Racial Equality (CORE), and the Nation of Islam.[23] BLACK HATE established the Ghetto Informant Program and instructed 23 FBI offices to “disrupt, misdirect, discredit, or otherwise neutralize the activities of black nationalist hate type organizations”.[24]

    A March 1968 memo stated the program’s goal was to “prevent the coalition of militant black nationalist groups” ; to “Prevent the RISE OF A ‘MESSIAH’ who could unify…the militant black nationalist movement” ; “to pinpoint potential troublemakers and neutralize them before they exercise their potential for violence [against authorities].” ; to “Prevent militant black nationalist groups and leaders from gaining RESPECTABILITY, by discrediting them to…both the responsible community and to liberals who have vestiges of sympathy…”; and to “prevent the long-range GROWTH of militant black organizations, especially among youth.” Dr. King was said to have potential to be the “messiah” figure, should he abandon nonviolence and integrationism;[25] Stokely Carmichael was noted to have “the necessary charisma to be a real threat in this way.” [26]

    This program coincided with a broader federal effort to prepare military responses for urban riots, and began increased collaboration between the FBI, Central Intelligence Agency, National Security Agency, and the Department of Defense. The CIA launched its own domestic espionage project in 1967 called Operation CHAOS.[27] A particular target was the Poor People’s Campaign, a national effort organized by King and the SCLC to occupy Washington, D.C. The FBI monitored and disrupted the campaign on a national level, while using targeted smear tactics locally to undermine support for the march.[28]

    Overall, COINTELPRO encompassed disruption and sabotage of the Socialist Workers Party (1961), the Ku Klux Klan (1964), the Nation of Islam, the Black Panther Party (1967), and the entire New Left social/political movement, which included antiwar, community, and religious groups (1968). A later investigation by the Senate’s Church Committee (see below) stated that “COINTELPRO began in 1956, in part because of frustration with Supreme Court rulings limiting the Government’s power to proceed overtly against dissident groups …”[29] Official congressional committees and several court cases[30] have concluded that COINTELPRO operations against communist and socialist groups exceeded statutory limits on FBI activity and violated constitutional guarantees of freedom of speech and association.[1]
    Program exposed
    The building broken into by the Citizen’s Commission to Investigate the FBI, at One Veterans Square, Media, Pennsylvania

    The program was successfully kept secret until 1971, when the Citizens’ Commission to Investigate the FBI burgled an FBI field office in Media, Pennsylvania, took several dossiers, and exposed the program by passing this material to news agencies.[31] Many news organizations initially refused to publish the information. Within the year, Director J. Edgar Hoover declared that the centralized COINTELPRO was over, and that all future counterintelligence operations would be handled on a case-by-case basis.[32][33]

    Additional documents were revealed in the course of separate lawsuits filed against the FBI by NBC correspondent Carl Stern, the Socialist Workers Party, and a number of other groups. In 1976 the Select Committee to Study Governmental Operations with Respect to Intelligence Activities of the United States Senate, commonly referred to as the “Church Committee” for its chairman, Senator Frank Church of Idaho, launched a major investigation of the FBI and COINTELPRO. Journalists and historians speculate that the government has not released many dossier and documents related to the program. Many released documents have been partly, or entirely, redacted.

    The Final Report of the Select Committee castigated conduct of the intelligence community in its domestic operations (including COINTELPRO) in no uncertain terms:

    The Committee finds that the domestic activities of the intelligence community at times violated specific statutory prohibitions and infringed the constitutional rights of American citizens. The legal questions involved in intelligence programs were often not considered. On other occasions, they were intentionally disregarded in the belief that because the programs served the “national security” the law did not apply. While intelligence officers on occasion failed to disclose to their superiors programs which were illegal or of questionable legality, the Committee finds that the most serious breaches of duty were those of senior officials, who were responsible for controlling intelligence activities and generally failed to assure compliance with the law.[1] Many of the techniques used would be intolerable in a democratic society even if all of the targets had been involved in violent activity, but COINTELPRO went far beyond that … the Bureau conducted a sophisticated vigilante operation aimed squarely at preventing the exercise of First Amendment rights of speech and association, on the theory that preventing the growth of dangerous groups and the propagation of dangerous ideas would protect the national security and deter violence.[29]

    Range of targets

    At its inception, the programs’s main target was the Communist Party.[34]

    According to the Church Committee:

    While the declared purposes of these programs were to protect the “national security” or prevent violence, Bureau witnesses admit that many of the targets were nonviolent and most had no connections with a foreign power. Indeed, nonviolent organizations and individuals were targeted because the Bureau believed they represented a “potential” for violence—and nonviolent citizens who were against the war in Vietnam were targeted because they gave “aid and comfort” to violent demonstrators by lending respectability to their cause.

    The imprecision of the targeting is demonstrated by the inability of the Bureau to define the subjects of the programs. The Black Nationalist program, according to its supervisor, included “a great number of organizations that you might not today characterize as black nationalist but which were in fact primarily black.” Thus, the nonviolent Southern Christian Leadership Conference was labeled as a Black Nationalist-“Hate Group.”
    Furthermore, the actual targets were chosen from a far broader group than the titles of the programs would imply. The CPUSA program targeted not only Communist Party members but also sponsors of the National Committee to Abolish the House Un-American Activities Committee and civil rights leaders allegedly under Communist influence or deemed to be not sufficiently “anti-Communist”. The Socialist Workers Party program included non-SWP sponsors of anti-war demonstrations which were cosponsored by the SWP or the Young Socialist Alliance, its youth group. The Black Nationalist program targeted a range of organizations from the Panthers to SNCC to the peaceful Southern Christian Leadership Conference, and included every Black Student Union and many other black student groups. New Left targets ranged from the SDS to the InterUniversity Committee for Debate on Foreign Policy, from Antioch College (“vanguard of the New Left”) to the New Mexico Free University and other “alternate” schools, and from underground newspapers to students’ protesting university censorship of a student publication by carrying signs with four-letter words on them.

    Examples of surveillance, spanning all presidents from FDR to Nixon, both legal and illegal, contained in the Church Committee report:[35]

    President Roosevelt asked the FBI to put in its files the names of citizens sending telegrams to the White House opposing his “national defense” policy and supporting Col. Charles Lindbergh.
    President Truman received inside information on a former Roosevelt aide’s efforts to influence his appointments, labor union negotiating plans, and the publishing plans of journalists.
    President Eisenhower received reports on purely political and social contacts with foreign officials by Bernard Baruch, Eleanor Roosevelt, and Supreme Court Justice William O. Douglas.
    The Kennedy administration had the FBI wiretap a congressional staff member, three executive officials, a lobbyist, and a Washington law firm. US Attorney General Robert F. Kennedy received the fruits of an FBI wire tap on Martin Luther King, Jr. and an electronic listening device targeting a congressman, both of which yielded information of a political nature.
    President Johnson asked the FBI to conduct “name checks” of his critics and members of the staff of his 1964 opponent, Senator Barry Goldwater. He also requested purely political intelligence on his critics in the Senate, and received extensive intelligence reports on political activity at the 1964 Democratic Convention from FBI electronic surveillance.
    President Nixon authorized a program of wiretaps which produced for the White House purely political or personal information unrelated to national security, including information about a Supreme Court Justice.

    Groups that were known to be targets of COINTELPRO operations include

    communist and socialist organizations
    organizations and individuals associated with the Civil Rights Movement, including Rev. Dr. Martin Luther King, Jr. and others associated with the Southern Christian Leadership Conference, the National Association for the Advancement of Colored People, the Congress of Racial Equality, and other civil rights organizations
    black nationalist groups
    the Young Lords
    the American Indian Movement
    the white supremacist groups
    the Ku Klux Klan
    the National States’ Rights Party
    a broad range of organizations labeled “New Left”, including Students for a Democratic Society and the Weathermen
    almost all groups protesting the Vietnam War, as well as individual student demonstrators with no group affiliation
    the National Lawyers Guild
    organizations and individuals associated with the women’s rights movement
    nationalist groups such as those seeking independence for Puerto Rico, United Ireland, and Cuban exile movements including Orlando Bosch’s Cuban Power and the Cuban Nationalist Movement;
    and additional notable Americans.[36]

    The COINTELPRO documents show numerous cases of the FBI’s intentions to prevent and disrupt protests against the Vietnam War. Many techniques were used to accomplish this task. “These included promoting splits among antiwar forces, encouraging red-baiting of socialists, and pushing violent confrontations as an alternative to massive, peaceful demonstrations.” One 1966 COINTELPRO operation tried to redirect the Socialist Workers Party from their pledge of support for the antiwar movement.[37]

    1. BarkinDog – during the very long Eyes on the Prize, one of the major black players makes an an aside regarding the relationship of the CPUSA and the Civil Rights Movement. According to him, they were big financial and body supporters. Just for those too young to remember, the SDS and the Weathermen were not the local tiddley-winks players. They were hard-core.

  5. People are begging to have their rights taken away. Please make the internet safe for us!! Weren’t the San Bernardino shooters radicalized on the INTERNET? Gotta take more of our rights…it’s the only way we can be safe!!!

    Ever Wonder Why the Most Mass Shootings Ever Have Happened Under Obama?

  6. Hey Dude, don’t make it bad
    Take a sad song and make it better
    Remember to let her into your heart
    Then you can start to make it better

    Hey Dude, don’t be afraid
    You were made to go out and get her
    The minute you let her under your skin
    Then you begin to make it better

    And anytime you feel the pain, hey Dude, refrain
    Don’t carry the world upon your shoulders
    For well you know that it’s a fool who plays it cool
    By making his world a little colder
    Nah nah nah nah nah nah nah nah nah

    Hey Dude, don’t let me down
    You have found her, now go and get her
    Remember to let her into your heart
    Then you can start to make it better

    So let it out and let it in, hey Dude, begin
    You’re waiting for someone to perform with
    And don’t you know that it’s just you, hey Dude, you’ll do
    The movement you need is on your shoulder
    Nah nah nah nah nah nah nah nah nah yeah

    Hey Dude, don’t make it bad
    Take a sad song and make it better
    Remember to let her under your skin
    Then you’ll begin to make it
    Better better better better better better, oh

    Nah nah nah nah nah nah, nah nah nah, hey Dude
    Nah nah nah nah nah nah, nah nah nah, hey Dude
    Nah nah nah nah nah nah, nah nah nah, hey Dude
    Nah nah nah nah nah nah, nah nah nah, hey Dude

    1. BarkinDog – least you could do is give credit to the Beatles for ripping them off.

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