New Message: Preserve existing comments while closing future comments?

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A new message was posted:

Address: http://frontier.userland.com/discuss/msgReader$14227

By: Tim Merritt (tmerritt at gsu.edu)

We have several educational blogs that show good uses for education, including valuable comments. Lately these sites have gotten piles of comment spam. We can remove the spam (though it's a slow, painstaking process), but how can we prevent future comments while leaving the existing ones available for future readers?

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