`find` finds nfs server?

I had to run find / -name foo > found.txt and stumbled over the following output:

...
find: /Volumes/MobileBackups/Backups.backupdb/mac/2014-12-17-162004/MacRoot/.DocumentRevisions-V100: Permission denied
nfs server localhost:/FjbUHyS_WAWZQyX9SZ1Wx9: not responding
nfs server localhost:/FjbUHyS_WAWZQyX9SZ1Wx9: is alive again
nfs server localhost:/FjbUHyS_WAWZQyX9SZ1Wx9: not responding
nfs server localhost:/FjbUHyS_WAWZQyX9SZ1Wx9: is alive again
nfs server localhost:/FjbUHyS_WAWZQyX9SZ1Wx9: not responding
nfs server localhost:/FjbUHyS_WAWZQyX9SZ1Wx9: is alive again
nfs server localhost:/FjbUHyS_WAWZQyX9SZ1Wx9: not responding
nfs server localhost:/FjbUHyS_WAWZQyX9SZ1Wx9: is alive again
find: /Volumes/MobileBackups/Backups.backupdb/mac/2014-12-17-162004/MacRoot/System/Library/DirectoryServices/DefaultLocalDB/Default: Permission denied
...

I'm not using NFS nor have I ever mounted a NFS volume. Where is this coming from?