This means DNS queries will not resolve for government employees if they point to Linode hosted machines.
I've verified this with USMC, USDA, & Sandia national lab. Heard that the top level domain linode.com was black holed due to its association with malicious activity as per a US-CERT Situational Awareness Report 10-015-01A UPDATE.
This is a big pain in butt for those of us that are grant funded or work with U.S. Government.