Point taken about tribe size. Remembering the BBS days, the only troubles we experienced were on the bigger systems where it became impractical to vet users co

Point taken about tribe size. Remembering the BBS days, the only troubles we experienced were on the bigger systems where it became impractical to vet users consistently. Newsgroups that were closed membership worked much better than open ones. Cryptographic identity makes this easier to handle, but it's not the only way. For example, on a system the size of Facebook, the only one spamming me is Facebook. This is because of the social nature of my group. I know everyone (more or less) and can kick them if need be. The spammers have to pay to play, which unfortunately isn't keeping it down to 0 on Facebook, but probably less than it would be normally.