[fulafel]

Being a country means you can make your own laws so the authority question has a pretty clear answer. Unless you disaviow national borders and state power and such stuff generally of course. See https://en.wikipedia.org/wiki/Sovereignty

[weberer]

Read the question you're replying to again. Its a question about jurisdiction.

[flumpcakes]

If it affects UK citizens, living in the UK, then there's jurisdiction. Either the entities comply, remove their services to the UK, or they risk sanctions/being arrested when abroad/etc.

Why should a US company harm UK citizens just because they're in the US?

If you want to serve a market in another country you have to follow their rules.

In this case, Imgur have been misusing UK children's information. Considering the laws are pretty similar, I suspect they're misusing EU children's information too.

[gr3ml1n]

> they risk sanctions/being arrested when abroad/etc.

That's the OP's question. Bluntly: if I'm here, and they're bloviating over there, what can they actually do about it?

[fulafel]

It was about authority, synonymous with jurisdiction, I understood it. A sovereign country can decide they have authority/jurisdiction in anything they want. For example various countries have decided they can legally assassinate people in other countries even though other counties might not agree.