Tim Bray is right, splogs are out of control.
This won't solve anything really, and the bots that are creating splogs will just be adjusted accordingly, but it seems that if you marked your RSS feed with the IP Address of the requesting browser/aggregator/bot you'd be able to track down and/or block that bot in the future from snagging your content. It'd just be stripped out in no time, but it might be able to make a dent...
The real problem though is twofold: 1) Google AdSense and maybe its competitors aren't properly vetting new accounts (are their any YPN-powered splogs out there yet?), and 2) They aren't punishing those who break their TOS. It should be very clear, if you create a site that's created solely to harvest links to generate traffic for advertising, then you get to be sued for damages. Then they need to follow through with a few real-world suits.
It's all about the money in these situations. Take away that incentive and the splogs will go away.