The RBL is a good, good thing. It's the last, best, hope for peace, and for a usable internet. It's not censorship, it's not bullying, it's just a good way for people to band together and protect themselves from danger.
The RBL is a list of IP addresses that send spam. Some of them are "innocent" relays. Some of them are dedicated spammers. It doesn't matter, for our purposes; they are sites that are contributing, in some way, to the spam problem.
So, what happens to the people on this list? Well, nothing, intrinsically - all that happens is that Paul Vixie stops accepting TCP/IP packets from them. Except, of course, that a lot of people have signed up to have their routers or mail servers use this same list to decide which packets or mail messages to reject.
A lot of people.
Is this censorship? No. No one is keeping anyone else from getting email or TCP/IP connectivity. Is this bullying? No. No one is threatened, forced, or cajoled. This is just self-government; people are able to more easily decide not to talk to people they don't like, or, more importantly, to decide not to talk to people that someone doesn't like, for a well-defined set of reasons people have agreed on.
The RBL has two functions, one necessary, and one desirable.
As a necessary function, the RBL works as a very good spam filter. It lets concerned admins throw away spam very early in the mail delivery process, with very litlle work.
As a desirable function, the RBL is a way for a large number of people to vote for responsible policies of network use. It lets every user of the list, every day, tell the people on the RBL that spam is not acceptable behavior. It lets people do this without a constant, time-consuming effort; it is a labor saving device on a scale rarely seen. It spares more people more annoyance, and more wading-through-filth, than an automatic pissing machine.
Comments? Questions? Email firstname.lastname@example.org.