RSS Aggravation

Are feeds implied licenses, or can they alter express ones? I don't think there's an easy answer, but a court could be asked this question before long as businesses built on RSS continue to explore what they can and should be doing with the material they aggregate. Marty Schwimmer (Bloglines, no thanks), Dennis Kennedy (don't make me put ads in my feed), and Robert Scoble (people who live in full post houses shouldn't throw republication stones) have more. Mark Fletcher expands and contracts.