Sometimes, reality just gets so fucked up that THEY have to do a 120 reset on The Matrix to restore normality. This is high on the list of things you don't want to see when you wake up on Monday morning. You better heed the warning, though. If you don't log out, you'll be forced out as the matrix shuts down, and probably suffer dump shock as your conciousness is forcibly returned to your body (see:shadowrun).

I can see this being an actual scenario or plot element in the future matrix sequels. As science progresses in the world, and as time passes, the technology has to improve, and history has to continue. Everyone would have their memory reset to a specific point in time, and the program could run all over again. Perhaps all human beings are massacred and replaced with fresh clones. After all, wouldn't it be needed to make sure that humans don't create the machines a second time, creating a matrix within a matrix?