Or both. Sorry, but you can't categorize something like this any other way. If any providers now filter for rfc-ignorant.org, emails may be bounced or sent to the spam folder - just because the operator of rfc-ignorant.org doesn't like the whois from DeNIC. By the way, the mail RFCs do not contain any indication (and certainly no mandatory condition) that a whois service must exist for a domain. So much for the technical competence of the operator of this idiotic list ...
It's bad enough that as a mail admin you have to deal with spam, trojans, viruses and similar nonsense - and the gigantic mountains of traffic that result. More and more often you also have to deal with completely brainless block list operators and similarly stupid mail admins who implement these block lists (and possibly even bounce emails because of the listing!).
And when you point this nonsense out to them, the standard line is: "RBL filtering has almost eliminated all my spam". Great. The fact that the email medium is more damaged by such incompetent fools than by the spam itself is of no concern to them. Let's just break everything, every idiot can be a mail admin today. It's disgusting.
(Found via fh).