I think they basically said that all Internet radio stations will have to start paying far more royalties each time a person listens to a song. This would effectively shut down all US based stations as there would be no way of paying this amount of royalties.
There was some attempt to fight the new legislation but what with the RIAA having millions of dollars to spend on lawyers and the legal systems lack of understanding of all things technical, it didn't work.
The final twist to the story is that many Internet radio stations figured they could get around the legislation by only playing non-RIAA member tracks. Unfortunately the RIAA has the right to collect money regardless of who holds the copyright, assuming that the artist will collect the money from the RIAA at a later date. Which is some kind of bullshit I'm sure you'll agree.
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