Thanks for posting the details, I had heard it was possible but could never find anywhere to access American TV for free. It is great to watch. I have no idea about how legal it is, I would be interested if anyone knows.
This is completely illegal, not to the end user but to the distributor.
Download this NOW, enjoy it while it lasts, it does exactly what it says on the tin and is a fantastic way to watch a wide range of tv channels (mostly US but some international, no BBC yet) as they're meant to appear. Fascinating.
I guess it's maybe something of a grey area. I can't see how watching FTA broadcast channels on it would be illegal - can't think which bit of law would prohibit it. Maybe watching pay channels on it would be actionable - but again, I can't really see how. It's not like pirating music, where you're stealing an item of something with a unit price. You're just watching a live stream of a thing.
As said on Digg somewhere, the company behind it just provides the technology (the software) for people to do such a thing, it does not promote it, endorse it or actually stream the TV networks themselves. It's up to the people who use it what's broadcast on it. This is how Asaurus and other filesharing software companies have escaped shutdown by governments.
First, as I've already stated, TVUNetworks provide only the technology, not any streams themselves. This should get them out of any trouble. Secondly they are based in China, who are not particually good at enforcing copyright laws, so it would be difficult to take action against them.
The only people who could easily get into legal troubles are those providing the actual streams.