Overview The use of " anti-virus " techniques in many modern worms recalls two stories: the " war " between virus writers and the possibility of a beneficial virus. This article examines both in light of recent events in the virus world. In early 2004, the release of Netsky began a rash of articles discussing " vigilante " coders trying to stop the spread of other worms. The war between Netsky'...

In Experiment I subjects were asked to judge whether an arrow was pointing up or pointing down at various heights inside a surrounding rectangle. They were faster on an arrow pointing up the higher it was in the rectangle, and they were faster on an arrow pointing down the lower it was in the rectangle. Experiments 2, 3, and 4 were designed to test sources for this"congruity effect." The intrus...