[nsp-sec] Romanian IP's being DNS-bad, botnet/spamnet controllers?

[Chris Morrow]

Howdy, would anyone else that runs largeish dns clusters have  
information about:

78.96.154.147
193.226.19.74
86.120.67.249

These 3 ips seem to REALLY like to hammer dns servers for MX (only  
actually) queries... they seem to be talking to the 'right' DNS  
servers (my dns servers when doing MX lookups for my domains).  I  
don't see anything odd in their origin ASN, CBL, spamhaus (aside from  
some PBL listings which dont' seem to apply here). Are these ips known  
to anyone else as having done boatloads of DNS lookups? I remember  
someone else in the content-game asking this recently, but I can't  
recall whom that was :(

-Chris
(google-security-person)