Knowledge and belief are orthogonal to one another. You can believe and not know (religious people), you can not believe and know (everyone with respect to anthropogenic deities that they do not believe in), you can not believe and not know (this usually involves some nebulous, poorly defined concept of 'god'), etc.
As far as claiming that affirming nonexistence of a god concept is just as invalid a position as affirming its existence, let's first define that god concept. Go with "Thor" or "Set" or "El" and I'd say that you have a much stronger case for nonexistence than existence, seeing as many falsifiable claims have been made regarding these god concepts, and these claims have been falsified.
Or setup a separate ARPA-owned network that no one can access except DOD employees.
This exists, it's called the SIPRnet. You can only access it from secure workstations in secure facilities, and in theory all the network hardware is also secure, etc., etc.
AFAIK, the only recent SIPRnet compromise was Bradley Manning, and that was more of a social exploit than a technical one.
8 Catfish = 1 Octo-puss