In response to Scoble, James says:
You can't really argue this point. The ads contain links that the site owner wanted you to see (he's paying for you to see them). By blocking them, you change the behavior of the web. See, this is why I simply can't get worked up over AutoLink. Given appropriate tools, I can decide whether I want to see pop ups or not. Google is providing me with a tool that lets me decide whether I want to see related information or not. Heck, I might as well rage against paid placement. Scoble blathers on and on about how AutoLink is an evil idea. Winer has been going on and on about it as well. I'll say the same thing I say to people who can't figure out the "change channel" or "off" switch on a TV or radio - you don't have to view/hear/read the content. It's an individual choice, and that's just fine. No one said you have to use Google. It's an open market for search engines guys - if this is an evil idea, people won't like it. If people don't like it, MS has the perfect opportunity to market their AutoLink free search engine.
Sorry, James, but I think you're missing the point. It is not a question of whether the user has the choice of whether to use Google or not. The problem, rather, is that the content publisher does not.
Copyright exists to protect the rights of the owner, not the consumer. It reserves in the holder the exclusive rights to reproduce, distribute, perform and display the work, and to license these exclusive rights to others as the holder sees fit. Just because the end user knows the changes are being made doesn't mean they are authorized to do so.
The Courts may decide that this is fair use or that it does indeed constitute an unauthorized derivative copy. However, the proper analysis will focus on the rights of the copyright holder, not the end user.
Update: Fred von Lohmann thinks we own our desktop and says, “mark up my webpages for me, butlers of the world, make my web more useful!”
See also: Martin has commentary and links on The Trademark Blog.