DoD Knowledge Base: FAQs
Because of security and bandwidth issues, the Defense Department blocks access to many popular Internet sites from department-owned computers.
Sites are selected on the basis of usage trends. This action is not an unfavorable characterization of these sites nor a restriction on their content. We recognize that being able to communicate with friends and family back home is of great importance to the morale of our service members. We have ensured that other means are available such as access via email, telephones, and other means are not affected by this policy. Access from privately-owned computers is not affected.