L. Todd Masco writes

...

On at least 3 of those lists, a list maintainer tried to take some arbitrary unilateral action and had to later back down because nobody was willing to put up with such shit.

Same thing happened when Coca Cola tried to change their formula:

Should we therefore conclude that Coke does not own coke?

If my and my friends don't like coke, we can't copy their secret formula and sell something in a red can with a white curve down the side and "Coca-cola" written on it in cursive lettering. We'll be in court in about four minutes. If me and my friends don't like the cypherpunks list, we can start our own list called "cypherpunks." We can even get the list of subscribers from toad (it's public information), and subscribe them all to our list, although they might not appreciate it so much. Or, if we really had a problem with the signature-requirement, we could start up our own list and actually subscribe our list to cypherpunks, and cypherpunks to our list. Everyone on our list would get all cypherpunks mail, and as well as mail sent to our list specifically. And cypherpunks would get our list. So if you didn't want to sign, you could join our RebelCypherpunks list which would be identical to cypherpunks except you could contribute to it without signing, and others on our list would get your posts. If you did want to sign, joining our list would be identical to joining cypherpunks, since all mail from our list gets forwarded to cypherpunks anyhow. "Ownership" of a mailing list isn't a simple thing. The exact instance of majordomo running on toad and administered by Eric is not "the cypherpunks list."