US parliamentarians have
called P2P networks a threat to national security.
It is interesting that, of course, harm is caused not by the networks themselves, but by irresponsible workers who post secret documents (military orders, accounting reports, personal data of employees, etc.) into the “shared” folder from which anyone can pull them off.
New laws that are being considered by the government are designed to combat this problem. The main fear of politicians is the fear that terrorists and spies will gain access to state secrets using P2P networks.