A team of physicists made an exciting finding at the same time as a team of competitors, wrote it up, submitted it to Nature, and then submitted the preprint to arXiv -- an archive that many astronomers and physicists race to submit to. However, the authors wrote in the comments that the paper was under embargo, according to Julianne Dalcanton at the Cosmic Variance blog. "The authors advertised a paper to thousands of interesting, engaged scientists, who are then supposed to keep their mouths shut so that the authors can get a paper into a particular journal," she writes. In the comments, the Nature astronomy editor weighs in to say that "anyone who posts to arXiv with a note 'under embargo' is mis-informed" and that authors are free to post to arXiv.