You could say exactly the same thing about hot-linking images. Or asking people not to share your telephone number.

Ignoring the legal issues, if someone asks you not to link to their website then the polite thing to do is not to link to it.

Of course there might be some cases where you might be justified in liking against the owner's wishes (for example criticism, review, etc.) - however if your just linking because it adds value to your own site, then frankly that's just being a jerk.

>You could say exactly the same thing about hot-linking images.

No, these are fundamentally different issues. Hotlinking an image causes the image itself to show up in the context of your content. Linking—not hotlinking—to the image is no different from linking to a story or any other piece of content available on the WWW.

If you don't want the rest of the Internet to be able to access your resource, don't give it a uniform resource locator. If you must, simply implement rights management. You are free to tell people not to link to your content, but they are free not to care, or even to be aware of your wishes.

I'm not saying newspapers should be granted any specific protection beyond other websites. I think any website should be allowed to ask someone not to link to them.

The URL protocol allows hotlinking just as much as it allows normal linking. What the protocol does and doesn't allow doesn't define the ethics or the situation.

I'm sure all the companies that want to control inbound links would love to have an inbound link based rights management system. However sites they want to block just use various redirect tricks to cover up the referer.

Providing a link to a website about X is the ethical equivalent of telling your friend where they can learn about X.

You missed the critical conditional of "when the owner's asked you not to do it".

A closer comparison might be passing information onto a friend, when the person who told you the information in the first place asked you not to pass it on.

No, I said what I meant. The ethics of the situation may indeed be driven by the conditionals, but the isomorphism is valid across all conditionals that you might apply. Thus, you can imagine some situations in which linking (or telling a friend) is unethical, just as you can imagine others in which it's not.

You can't even compare it to hotlinking, a suitable equivalent of hotlinking is hosting the content from the other website from your website. The web is built on linking if you don't want other people to link to your website you can add redirects and denies based on where people are coming from and see how long your site lasts.

Is your objection technical rather than philosophical then ? - you don't object to controlling who links to your site (or at least ability to view) but rather to the control being human driven rather than automated (via robots.txt, refers, or a similar method) ?

Sure, the web is open you can choose to run your website the way you want it, if you don't want people linking to your content you should stop them. But the burden should be placed on the website owner and not those who are linking to the content, this isn't something like stealing content that we are talking about (which should be despised) it is simply sharing content with others no different than telling someone to check out a book named Fill in the blank.

Robots.txt is great for something that is automated like scraping but otherwise it is severely limited.