It is a reference to the book/movie Fahrenheit 451 [1].

[1] https://en.wikipedia.org/wiki/Fahrenheit_451_(disambiguation...

My favourite part of GDPR is getting to use 451 legitimately everywhere.

I'm not sure it is really though is it?

It's legitimate in the same way that '451: we want to load up our site with so much javascript your computer catches fire and burns your house down, but that's illegal in your jurisdiction so this site is Unavailable for Legal Reasons' is.

To me 451 is like 404 (nothing here) and 410 (was something here but now there isn't) - it's a further progression/specificity to 'was/sort of is something here but it's not presently available for legal reasons'.

Common obvious one is DMCA takedown notices, but it might also be an injunction, or even accidentally published while still under embargo - or deliberately to prime SEO (not advice) - or NDA, etc.

It’s a Carol business decision that letting Alices & Bobs view content for free isn’t cost effective if Carol isn’t allowed to track Alice and Bob without their permission and make money by letting Eve, who is unknown Alice and Bob, to build up a detailed profile of Alice and Bob.

Project Guttenberg in Germany (and The Pirate Bay in the USA, I think) would be 451.

Why is Project Gutenberg illegal in Germany?

Court order regarding blocking specific books, the project itself isn’t a problem: https://cand.pglaf.org/germany/index.html

I don't know. "Our site is so hostile to user privacy that it's illegal in some places" isn't exactly something I'd be proud of. Nor is, "We might be in violation of GDPR and we might not--we have no idea so we're going to just block you."

> Nor is, "We might be in violation of GDPR and we might not--we have no idea so we're going to just block you."

It’s not something to be proud of, but it is something I am sympathetic about. Modern laws (not just GDPR) are long and the language is often hard to understand.

I believe that laws must be simple enough to comprehend, or else they will not be comprehended and thus will be violated even by people who want to follow them — the phrase would be better if it was “ignorance of the law cannot be an excuse”, because that works both ways.

Even if you never actually did anything wrong, demonstrating compliance with GDPR delays releases and adds costs that never end.

451 F = the temperature at which fire burns

It's the ignition temperature for paper. Fire burns at different temperatures depending on the fuel source, even paper will each a much hotter temperature after ignition.

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It's an approximate and somewhat mythical value, popularised by Ray Bradbury's novel. Actual ignition point varies bu 100+ °F. Experience this past year with sourdough baking --- on parchment paper at 290°C (550°F) --- shows that though the paper browns, it does not combust. (Possibly affected by thermal mass / moisture of bread loaf.)

https://slate.com/technology/2012/06/ray-bradbury-death-does...

</pedant>

Not better than 420. You could say that 420 is the highest of all status codes