I understand Tim Marman's point about copyrights - he's correct in saying that the medium doesn't change the law:

As a producer, I have the ability to define how others can use my content. If we want to encourage sites to syndicate their content, we have to ensure that they can prevent people from using content in ways they don't want to allow. This is at the heart of a lot of the Creative Commons licenses, including the Attribution-NonCommercial license I publish my content under.

This license basically says you can repurpose my content here as long as 1) you attribute the content to me and 2) don't use it for commercial purposes. In other words, I want to allow people like Scoble to post my content on his link blog, but I don't want someone taking my content and using it in a book.

That's fine. The trouble is, that horse left the barn a long, long time ago. Take Search Engines, for instance - they are clearly being used for commercial purposes. They reproduce partial (potentially full) content wrapped in a different site's advertising policy. Take news aggregators - if you include full content in your feed, you've ceded control over how that content will be used - maybe not from a de jure standpoint, but that's irrelevant - you've done so in a de facto fashion. Any consumer of your RSS feed might be using their aggregator for commercial purposes (I certainly use mine that way). Are they in violation when they display your content locally using a custom stylesheet? What if we have an aggregator that works like the free version of Eudora, where it throws ads at you?

This isn't really new territory we're in - copy machines crossed this line (with respect to books and magazines) a long time ago. Back when I worked in an office, in the days before the internet was visible to most people, the local admins routed a folder of interesting stuff around. Much of it consisted of magazine articles copied in full and passed around. That was almost certainly a copyright violation of some kind - should everyone in the office have been arrested? There's kind of an informal understanding with copy machines - we ignore "the small stuff". The difficulty here is that we haven't come to a shared understanding of what constitutes "the small stuff" on the web yet.