Joe points out that copyright resides with the author, and there is a disclaimer to that effect at the bottom of the page. It is legally sound in most countries, through certain conventions, and there you go.

However, the owner of the hosting webpage does have responsibilities under their own country laws to moderate and posters have responsibilities under their own country laws to post legally. You post in your country, under your country's adherence to copyright, ownership of material etc.

US law is irrelevant to UK posters and UK law is irrelevant to US posters. Icelandic law is often the subject of jokes on UK television.

It does, as Steve points out, make it important that you think before posting. One joker on here seems to think Scottish law doesn't apply to what he posts because it is an American hosted website.

Ignorance is not an excuse, although I'll accept in his case it is a common factor.