99% of the problem with viruses, worms, et al is due to you-know-who writing software that allows this to happen.
If there is going to be licensing and regulation (and as something of a libertarian, I'd say that's a big "if") it would be better aimed at making the software giants improve their trashy programs and at getting rid of all the pop-up junk and other garbage that is on the net.
The drawback would be that any sort of official regulation to do that would undoubtedly stifle the open and free nature of the Internet for everyone else too.
