So... only .co.uk, or full 3/4 of the internet, including Tumblr?
This is, of course, is a question for what counts as "operating in Britain". A site that is running on servers in Britain? A site that is owned by a British company? A site that happens to be available on the greater internet?
Gosh, countries and borders became relics when the internet got spread wide enough.
Broadly, UK law is restricted to UK companies for material which is illegal to post. So libelous sites hosted outside the country aren't censored, because the libel isn't 'located' in the UK (yes, this is a tortured analysis).
But the UK has more recently established a China-style firewall that restricts access to sites hosted anywhere, based on where you view from. Originally, it was implemented to block access to torrent sites. And of course, at the time everyone swore "it's just the torrent sites, there will never be a slippery slope!"
But now it would age-gate pornography viewed from any UK IP address. Well, the content they can find anyway - they'll have to either run a blacklist (catching only large, paid sites) or a blocking filter with a whitelist (blocking all kinds of legitimate content - usually this ends up blocking sexual health sites). And yes, Tumblr is hopeless, there's really no way to know what a given page will have on it.
So it's the authoritarian, cut-off-access bit, but it still won't work.
... then, as of a couple of years ago, they started using it to block torrent sites. So it goes.
/going rather offtopic afterwards
What's also not good is how ugly the internet became. Even in the 90s it was rather easy to stumble upon unexpected material; a prime example would be if you'd searched "Spice Girls" somewhere in ~1996 on Altavista - the results were definitely not showing the pop band.
I'm well aware how formerly extreme things, like in fashion or in porn is slowly merging into the mainstream, and so the dark pits of the internet are becoming more accepted. It's also true that bullying, tweet wars, doxing, etc, due to the lack of critical mass of internet users, were not present, and that they are actual, existing issues which should be addressed, but no one knows, how.
So no, I'm seriously against a porn database; it's not helping anything, not solving any real problems. The "protect the children" is bullshit; I'm guessing many who are supporting the idea would get a heart attack should they learn how aware "kids" are compared to them, and this is not just due to the internet. These people are the same by the way who grew up in the 70s...
Anyway, there are problems which needs attention and regulations, but that's not porn.
This not a really good analysis.
In Europe, the state is responsible of guaranteeing that the basic Human Rights are protected for all of its citizens. Than includes the right to education, health care, proper nutrition, shelter, security, etc. In general, the state does not intervene in private matters as far as this does not jeopardize the former. It's for a reason that laws about same sex marriage, soft drug legalization, etc. are passed in Europe decades before than in the US.
In this case, with its puritanism, UK is closer to the US than to West Europe.
No, it's not. What are you talking about?
The US is more like Western Europe, in fact the US is probably even more liberal than Western Europe, when it comes to porn. The UK is puritanical all by itself, and closer to, say, Saudi Arabia.
Here in the US, we produce all kinds of porn. California (LA mainly) used to be the hub for it, but it's spread out from there and now it's being made all over; you can find people looking for porn performers on any city's Craigslist now. We don't have any kind of "great firewall" to protect us from porn. We don't have proposals to make citizens get "ID cards" to view porn online. We don't have weird anti-porn laws against things like "face-sitting" (remember the flap in Britain a few years ago about that? They had women sitting on men's faces in front of government buildings to protest the ruling), or any other regulation on what kinds of positions are allowed to be shown in porn. It's pretty much totally unregulated over here. The industry does some internal self-regulation, but it's not government-imposed, and there's lots of small, independent producers (basically anyone with a camera) who aren't part of that.
Don't lump us Americans in with British prudery. We have some prudishness problems in parts of our society in "meatspace", but on the internet, it's the Wild West.