Those millions of dollars of damages to computers is a result of the hackers benifit because the hacker can hack into banking accouts, steal personal information, and lots of other things you probably wouldn't think about.
The viruses are made by very intelegent people, so the virus is not east at all to track. New viruses are being made up, which means that we have to keep creating new ways of stopping them. They are just one more thing to add to worries in the world.