One frantic computer manager who phoned the SPAN office refused to believe John's analysis that the worm only pretended to erase data. He claimed that the worm had not only attacked his system, it had destroyed it. `He just didn't believe us when we told him that the worm was mostly a set of practical jokes,' McMahon said. `He reinitialised his system.' `Reinitialised' as in started up his system with a clean slate. As in deleted everything on the infected computer--all the NASA staff's data gone. He actually did what the worm only pretended to do. The sad irony was that the SPAN team never even got a copy of the data from the manager's system. They were never able to confirm that his machine had even been infected. All afternoon McMahon moved back and forth between answering the ever-ringing SPAN phone and writing up NASA's analysis of the worm. He had posted a cryptic electronic message about the attack across the network, and Kevin Oberman had read it. The message had to be circumspect since no-one knew if the creator of the WANK worm was in fact on the network, watching, waiting. A short time later, McMahon and Oberman were on the phone together--voice--sharing their ideas and cross-checking their analysis. The situation was discouraging. Even if McMahon and Oberman managed to develop a successful program to kill off the worm, the NASA SPAN team faced another daunting task. Getting the worm-killer out to all the NASA sites was going to be much harder than expected because there was no clear, updated map of the SPAN network. Much of NASA didn't like the idea of a centralised map of the SPAN system. McMahon recalled that, some time before the WANK worm attack, a manager had tried to map the system. His efforts had accidentally tripped so many system alarms that he was quietly taken aside and told not to do it again. The result was that in instances where the team had phone contact details for managers, the information was often outdated. `No, he used to work here, but he left over a year ago.' `No, we don't have a telephone tree of people to ring if something goes wrong with our computers. There are a whole bunch of people in different places here who handle the computers.' This is what John often heard at the other end of the phone. The network had grown into a rambling hodgepodge for which there was little central coordination. Worse, a number of computers at different NASA centres across the US had just been tacked onto SPAN without telling the main office at Goddard. People were calling up the ad-hoc crisis centre from computer nodes on the network which didn't even have names. These people had been practising a philosophy known in computer security circles as `security through obscurity'. They figured that if no-one knew their computer system existed--if it didn't have a name, if it wasn't on any list or map of the SPAN network--then it would be protected from hackers and other computer enemies.