Other users were treated to anti-authoritarian observations of the paranoid:
The FBI is watching YOU.
or
Vote anarchist.
But the worm did not appear to be erasing files on these systems. Perhaps the seemingly random file-erasing trick was a portent of things to come—just a small taste of what might happen at a particular time, such as midnight. Perhaps an unusual keystroke by an unwitting computer user on those systems which seemed only mildly affected could trigger something in the worm. One keystroke might begin an irreversible chain of commands to erase everything on that system.
The NASA SPAN computer team were in a race with the worm. Each minute they spent trying to figure out what it did, the worm was pushing forward, ever deeper into NASA's computer network. Every hour NASA spent developing a cure, the worm spent searching, probing, breaking and entering. A day's delay in getting the cure out to all the systems could mean dozens of new worm invasions doing God knows what in vulnerable computers. The SPAN team had to dissect this thing completely, and they had to do it fast.
Some computer network managers were badly shaken. The SPAN office received a call from NASA's Jet Propulsion Laboratories in California, an important NASA centre with 6500 employees and close ties to California Institute of Technology (Caltech).
JPL was pulling itself off the network.
This worm was too much of a risk. The only safe option was to isolate their computers. There would be no SPAN DEC-based communications with the rest of NASA until the crisis was under control. This made things harder for the SPAN team; getting a worm exterminating program out to JPL, like other sites which had cut their connection to SPAN, was going to be that much tougher. Everything had to be done over the phone.
Worse, JPL was one of five routing centres for NASA's SPAN computer network. It was like the centre of a wheel, with a dozen spokes branching off—each leading to another SPAN site. All these places, known as tailsites, depended on the lab site for their connections into SPAN. When JPL pulled itself off the network, the tailsites went down too.