Keep in mind that some of these "clueless folk" may expect individually assigned CIDRs to be registered accurately, and are complaing to the registered contact for the block. If these blocks aren't registered/SWIPed appropriately, your argument is weak.
Last time I looked, most mailservers only live on /32s. Blocking these is in general sufficient. There are at least 2 ways to do this in a scalable manner (for both see http://maps.vix.com/), and I'm sure there are more. "Escalating" higher doesn't necessarily help. Europe (for instance) works on the Local-IR basis rather than SWIP. As a local IR I have (for instance) a /16 I'm assigning out of. I have customers of customers of customers who have had open relays. When people manage to use whois.ripe.net not whois.apnic.net, I occassionally see complaints about this. In every case (well I hope so), my customer has been correctly listed in the RIPE DB. My customer may or may not be responsive. But tracking this down to the customer's customer's customer is difficult. Surely the best thing to do is block the /32 if it's causing problems. I can't see what you gain by (say) blocking the /16. The other thing you can persuade people to do is run the RBL. Currently we run the BGP version, so if one of my customer's customer's customers is being abused as an open relay, they'll lose all connectivity to their mail server, not just to your network. This normally makes them fix things quickly (yes, we don't distribute-list out our own customer ranges from the RBL). Running your own "blacklist" rather than using generally available lists has its disadvantages (remember it's easy to add and subtract to/from something like the RBL and personalize it somewhat). In any case, I contest your statement that Europe (don't know about AP) is noticeably behind. If I look at the locations of the relays on the spam that gets through here, the vast majority are in the US. Assuming spammers don't have some perverted addiction to sending spam to the US through Europe and spam to the UK from the US, I think your maths may be a little awry (or possibly the RBL has already cured the European site problem). -- Alex Bligh GX Networks (formerly Xara Networks)