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If the webring is structured in such a way that it isn't visible to Google then it's no win/no loss for the site.
Webrings, much as I personally dislike the way they are presented, can actually be very good for the user (thinking of craft type webrings I've seen in particular) and a great way for small sites to build a network within their field. Certainly many of them are much more on-topic and of interest to the surfer than your average links page.
I haven't yet seen a webring that I've thought "oooo... they've done that for Google's sake!"
However i'm sure google gets far too many spam reports to attend to every individual one, so whether they will do anything about it is a rather different question.
Somtimes it helps if you mention your webmasterworld nick in the spam report somewhere.