From the horses mouth:
We often get the question if the DX-Tuner concept is legal. And it is. We are allowed to put up a scanner in any country where scanners are allowed. Site operators present their scanners to the public "un-intentionally" for a non specific frequency. As the streaming is "not intentional" of a fixed service, the site operator is not viable for any copyrights or telegraph-acts as the tuning and listening is done by others and without his knowledge.
It is merely up to the listener to take responsibility of its actions. It is the "telegraph act" in each country that applies. Almost all Telegraph acts have the same basic rule: You may not forward any messages heard on scanners to a third party.
It is one thing to listen in to an airband receiver yourself, it is completely different to re-broadcast. The law states you cannot pass on details of what you hear - surely this is what this site does - and charges for it!
Can you not recognise, that while the law is being broken, albeit, it's hardly the scale of murder, the website in question is a valuable aid to people like me (and believe me, the site has many, many members) who are generally interested in hearing Gatwick radar or Johannesburg ATC when they wouldn't otherwise be able to?