This brings us to another point, an important one. The behavior of these known viruses is well known and methods for their prevention exist. If you get a virus you will most likely get one that is well understood. 90% of the virus cases I run into are of the same virus. By finding out how these viruses work and what can stop them, Mac owners can protect themselves. Just as there is no protective measure that a demented programmer cannot circumvent, there is no virus that a helpful programmer cannot defeat.