After two years of mass-mailing worms, time to do the arithmetic. A simple SI epidemic model fits the propagation curves we have observed, and the model has predictive power that is uncomfortable to look at directly.
Another mass-mailing worm has emerged. ExploreZip is similar to Melissa in propagation but materially worse in payload. The trajectory I outlined in March is on schedule, and on the wrong side.
A small fireworks animation arrives in your inbox. It runs. It hooks WSOCK32. From now on, every email you send carries a copy of itself. We have crossed a threshold and most people have not noticed.