Highlighting the threat posed by virus programs, the New York Times reports that last October and November, large numbers of computers in Israel were infected with a time bomb program that if not detected would have erased all files stored on the machines on May 13 1988, the eve of the fortieth anniversary of the creation of Israel out of the old Palestine; even before the trigger date, the program was instructing personal computers to slow to a fifth their normal speed after they had been on for about 30 minutes, and was periodically putting garbage up on the screen.