I went to https://glbse.com/ and see it is closed. It was a stock exchange for shares of companies denominated in Bitcoins.
Does anyone know why it closed?
It appears that Nefario, the person operating GLBSE, decided to go against all bylaws and terms of service and just close GLBSE. That part of the story was explained by theymos. It it still unclear, however, why he did it.