As a CISSP I am not a bit surprised. These are all the result of untrained or inadequately trained users.

Re: Classified U.S. military info available over P2P.

The fact that classified information is on computer systems with unencrypted access to the internet is a breakdown in security procedures. The CISO's for the network have some resposibility however, for failing to have software that checks the security of systems accessing their networks.