Trying to piece together the details, here's my undewrstanding:
- Until recently, major British residential ISPs were blocking access to torrent/pirate/porn sites for their customers ("BT, Virgin Media, Sky, TalkTalk, EE, and Plusnet account for the majority of the UK’s residential internet market")
- Cloudflare has recently been ordered by courts in the UK to block access to these torrent/pirate/porn sites
- The reason that Cloudflare is involved is because many of these sites use Cloudflare as a content delivery network. A CDN is <waves hands> basically an application-layer distributed cache that sits between end users' web browsers and the origin HTTP servers that they're trying to access.
- Cloudflare geolocates clients connecting to its CDN. It undoubtedly has many reasons to do this, besides just court-ordered geoblocking: these would include routing queries efficiently within its globally distributed datacenters, DDoS prevention, bot blocking, etc.
- Cloudflare's geolocation techniques are, unsurprisingly, more sophisticated than just determining a country based on a client's IP address.
If I've got all that right (do I???)… then the tl;dr is:
It used to be possible for UK users to circumvent the blocks of these sites simply by using any VPN to acquire a non-UK IP address. Now the order to block these sites has been imposed on Cloudflare, which plays a critical role as an intermediary in distributing their content in a scalable way. For a variety of reasons, some of which end-users probably approve of and others not, Cloudflare uses more sophisticated techniques to geolocate clients. So "just use a VPN" is not enough to circumvent the blocks anymore.