Let's not forget the exploration issues. While a virus can be purely destructive without any interesting code in it, some people really push things forward and get some dangerous tools out there. In all honesty, I'd rather have such things happening, than some 'ingenious' blackhat taking down the county powergrid with some virus. In a sense, while exploits usually refer to remote systems, I guess we can think of virii as exploits of local systems, in order to [but not only] crumble that system.

ghostofanonion, while I can understand sometimes MS haters tend to be very biased in their comments about the company [we all are biased some way, but I'm dealing with the quality of their arguments here], the issue here is, indeed, that the company has repeatedly released software just waiting to be exploited in malicious ways. It looks more like a test-OS for future H/C rather than a serious OS. The very fact it is more common should determine the software giant to secure everything better. I read somewhere - unfortunately don't have the link anymore - that if source code to Windows was released, some stuff could be found in there that may posses a threat to national security if it would be known. And, btw, it was a MicroSoft official that declared that [interestingly enough, shouldn't the NSA be investigating if something like this is out in the open? Are commercial rights more important than individual freedoms?]