Jon at MobileTracker has just announced that he’s switching his RSS feed back to a summary feed rather than the full feed due to copyright violations and a number of sites who were publishing his full feed without permission. I’ve also had this same problem and found that a summary feed is the only real way of stopping the violation which not only breaks copyright but also creates duplicate content for your blog (and that of the one copying you ironically).
Read about it at MobileTracker – RSS feed update
About Darren Rowse
My name is Darren Rowse and I’m a full time Blogger making a living from blogs like 
Reading your own content at other sites with only small links is very troubling. Especially when it’s all of your content. I really didn’t want to have to do that, but having a full text feed is like wearing a kick me sign, it just opens you to a world of ass kicking.
yeah that must be frustrating Jon – I had a similar thing a while back now and had to do the same thing with my feeds.