We turned off editing till we figure out how to avoid the problems
we've been having of people turning all the links into pointers
to porn pages.  None of us have time to moderate it so I think we're
going to be stuck with some form of authentication and maybe even
a list of possible editors.

Perhaps we can just use the same authentication as copying from sources,
i.e., you have to get an update account and login when editing?  It might
even be sufficient to say that your IP address has connected and authenticated
to sources in the recent past to let you edit.