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Error 451: Unavailable for Legal Reasons

|The Volokh Conspiracy |

I had somehow not heard of this HTTP status code until now; it was adopted in 2016, and it's recommended as a more specific substitute for 403 Forbidden or 404 Not Found. Nice.

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11 responses to “Error 451: Unavailable for Legal Reasons

  1. I must only smile.

  2. That is so nice. Wikipedia of course already notes the connection in both directions.
    Related:
    1) I see the IETF RFC says that responses using this status code SHOULD include an explanation, in the response body, of the details of the legal demand.
    2) So, it might be very interesting to someone concerned about internet freedom to have a web crawler filter on status 451 responses and collect these legal demand details.
    3) .. Or it might not: The RFC explicitly states that use of the 451 status code is not mandatory, and that even when it is used, inclusion of the legal demand details isn’t mandatory, either.

    1. 3) .. Or it might not: The RFC explicitly states that use of the 451 status code is not mandatory, and that even when it is used, inclusion of the legal demand details isn’t mandatory, either.

      None of the status codes are mandatory. I can happily give you back a status code of 200 (OK SUCCESS) with a blank page insulting your mother all day long if I want.

  3. Note that RFC 1149, A Standard for the Transmission of IP Datagrams on Avian Carriers (https://tools.ietf.org/html/rfc1149 dated 1 Apr 1990), implicitly places restrictions on the size of the legal message.

    “The IP datagram is printed, on a small scroll of paper, in hexadecimal, with each octet separated by whitestuff and blackstuff. The scroll of paper is wrapped around one leg of the avian carrier. A band of duct tape is used to secure the datagram’s edges. The bandwidth is limited to the leg length. The MTU is variable, and paradoxically, generally increases with increased carrier age. A typical MTU is 256 milligrams. Some datagram padding may be needed. Upon receipt, the duct tape is removed and the paper copy of the datagram is optically scanned into a electronically transmittable form.”

    1. I made this image a few years ago at work, where we coming up with lolcat memes for network-related things:

      http://plover.net/~agarvin/rfc1149.jpg

    2. Is that restriction applicable to African Swallows, or just European Swallows?

  4. Thanks, I had a sneaking suspicion that the accepted etymology of “bandwidth” was for the birds.

  5. Error 452: Black Helicopters will be with you shortly.

  6. I take it that servers operated by the Judean People’s Front are exempt?