An anonymous reader writes: MIT has posted a letter to campus newspaper The Tech providing a timeline of last weekend's "gunman" hoax. On Saturday morning, Cambridge MA police were contacted via Internet relay by a tipster who claimed that a someone wearing armor and carrying a "really big gun" was in Building 7 at MIT (the Massachusetts Ave. entrance to the Infinite Corridor) and was heading towards the office of MIT President Rafael Reif. The call continued for 18 minutes, with the caller eventually claiming that the gunman was seeking to avenge the suicide of Aaron Swartz, who was being prosecuting for alleged illegal downloads of millions of journal articles using MIT's computer network. The caller also identified the gunman an MIT staff member, who has since been questioned by police and cleared. MIT has been criticized for waiting 1 1/2 hours before sending a campus wide alert after the call was received.