A suspicious package left in front of the Chula Vista courthouse today turned out to be a backpack containing vintage Playboy magazines. Authorities, including the sheriff's department bomb squad, were called to the courthouse at 500 Third Avenue after the abandoned backpack was found at about 8:45 a.m. Shortly before 11 a.m., authorities gave the all-clear after investigators opened the backpack and found the collection of Playboy magazines. Despite the investigation, the courthouse was not evacuated and workers inside continued to conduct regular business.