They might as well call it Operation Could-Not-Possibly-Go-Wrong. >Companies breaking the rules set out in the Digital Economy Act face being blocked by their internet provider. Seems to imply it would be the burden of individual sites. I'm sure many of which already have low margins since advertising in this space is extremely hard. So I'm going to guess most of them would sooner IP block all of Europe before bother…
A company operating outside the UK's jurisdiction wouldn't be affected at all from my reading of that. The UK could direct UK ISPs to block noncompliant sites entirely, but then they're in the position of trying to enumerate every site in the world that hosts porn. Good luck with that.
Web-filter companies: "challenge accepted".
Make no mistake, there is an entire industry which has been dedicated to this exact task for decades now. They will be very happy to help the UK government... for a fee.