Three Amicus briefs have been filed with the Supreme Court to hear the Kirby Heirs versus Marvel law suite. The suit claims that Marvel does not own copyright to Kirby's many characters, noticeably the Xmen and Fantastic Four. They Kirby folks have lost on a number of court rulings but the Supreme Court could change that and it is increasingly likely that they will hear the case.
If they won the Kirby folks would be due alot of money I suspect.
Just for the record, I have no idea what an Amicus Brief is.