++ 21/05/15 22:04 +0200 - Jurre van Bergen:
I got the same message yesterday, I asked leaseweb to put our exit node(hviv103) in a "dirty" ip-block and asked sectoor for a clarification on what happened. No reply to date of any party.
This DNSBL has a fairly straightforward listing for an IP-address: ((the IP-address itself is a Tor exit-node OR the IP-address is within a /24 that has some other IP-address with a Tor exit-node) AND the Tor exit-node(s) allow clients to connect to a list of about 15 different ports). Administrators are supposed to use this list as a scoring mechanisme, not for blocking. Of course, any administrator is free to use this DNSBL he or she wants.
There's not much you can do - other than just not running the Tor-node.