I'm not a big fan of Murdoch, but it's an interesting discussion that should go beyond the obvious technical arguments.
If Google started copying a full news site verbatim and offer its content when people search for news, that would definitely be wrong, robots.txt or not.
Strict copyright includes fair use exceptions and so on. Where fair use stops and infringment starts is an interesting discussion for me.
The GP was hyberbole that doesn't add anything to the debate. Ironically that's exactly what happens all the time on Slashdot.
If you're making the argument that the company that is automatically spidering your content should stop then your case is somewhat undermined by failing to take the simple steps to prevent aforementioned spidering.
Are you saying that if your content doesn't have a
robots.txt, then everyone is allowed to copy the content
of the site with no restrictions whatsoever
No, he is saying that if your content doesn't have a robots.txt, then everyone is allowed to index the content of the site with no restrictions whatsoever. After all, you are publishing it to the world. The fact that technology and automation are involved is irrelevant: the process is identical to me telling you that paper newspaper X had an article on Y in it's Jan 23rd, 2005 edition.Simply updating robots.txt won't effect Google at all and will blow what little leverage he has left.