You probably think you know what a link is. But even if you go read the explanation in the Wikipedia article I just linked to, I would suggest that you may still not know.
A link is speach.
For example, if I tell give you directions for how to get to the closest Jack in the Box--"go east on Westheimer, then turn south on Chimney Rock and it's there on your right hand side", that is much like a link. I'm telling you where you can find something.
Note how preposterous it sounds to suggest that the sentence I wrote telling you how to get to the thing is the same same as the thing itself. It is not a thing, it is a reference to a thing.
An internet hyperlink is much the same way. For example, let's say you wanted to know how to find the blog entry here that talked about the upcoming American Internet Service Provider censorship regime:
If you break it down, I'm simply telling you, "go to the web (that's the http:// part), once there, go to expandfairuse.org, the year 2012, May, to an article titled 'Hopefully our ISP's are dragging their feet'".
They are directions, not the thing itself.
So as I explained in my explanation of bittorrent, bittorrent sites, for example, contain no copyrighted material whatsoever. They merely link to where you can find it.
The point is, when you censor someone for linking to something, you are censoring speach, directions, thoughts, ideas. And you're not even stopping the sharing of the copyrighted material which you think you have a right to remove from the internet.
Further, it makes Google's acceptance of hundreds of thousands of Digital Millenium Copyright Act (DMCA) requests to remove links to copyrighted content from their search engine even more baffling. They aren't even fighting it.
I guess it's good that they are disclosing the massive censorship regime going on in America already. We sure don't need more, new, even worse laws to make "content providers" more powerfully destroying free speech on the internet than they already are. As it is, acccording to the article, Google still denies about 2% of the requests, including such things as a tv studio wanting them to remove links to unfavorable television show reviews.
What, you mean we can't trust Hollywood to censor the internet reliably? Shocking, I know. I know I, for one, was counting on them to save me from myself.