IIRC, this novel idea has been filed multiple times (and may have been granted as well) at the USPTO at different times. I believe that this is because the USPT

IIRC, this novel idea has been filed multiple times (and may have been granted as well) at the USPTO at different times. I believe that this is because the USPTO sometimes leaves it to the interested/affected parties to raise complaints and go through these rather than do the donkey's work of exhaustive prior art search.