Every now and again the nameservers in /etc/resolv.conf on my CentOS-6.5 server are commented out. I used to think this was the fault of NetworkManager, but I've stopped running that on the server (using the network service instead) and the nameserver removal still occurs.
I'm baffled by the motivation for this, as I can't think of any situation where it would be of advantage to have no nameservers listed.