I am sure that this came along many times, but I was not able to search for it through the mailing list.
OK, so to start, users without account (anons) contribute a lot of content, at least as typo fixing, etc., and many established users started as anons.
However, it is also true that the vast majority of vandalism is committed by anons, and it takes a tremendous energy to police the more than 1.7 milions articles for vandalism.
Hereby I suggest that only people with account be allowed to edit, and that they also suppy an email address when registering, which is then confirmed by sending an email to the supplied address and having the user clicking on a link.
This is quite standard nowadays on the vast majority of websites which allow more than just reading things, and people are rather used to it. It takes little time too to register and confirm one's email.
I am aware that this may decrease somewhat the number of people who get hooked on Wikipedia and the amount of contributions. I'd argue however that Wikipedia is at a stage now where it has a very large amount of users, articles, and recognition. At this stage we should care a bit more than in the past about the quality than the quantity of users and articles (while of course we should hope that the community and the number of articles will increase).
In short, I believe that having people make account and confirm their email is going to bring much more gain than loss.
Comments?
Oleg Alexandov