Just alert your posting and ask for account removal. Not easy but works.
I recently found out that several sites, including CNET(!) are blacklisted on this site (accountkiller.com) because it's all but impossible to delete your account.
In the context of the recent privacy buzz... shouldn't large websites always provide an easy way to delete your account and remove your digital trail?

Chowhound
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GameFAQs
GameSpot
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TechRepublic