Well, they have a web form to report wrong doing: plagiarism, spam, stolen identity and etc. I sent report through this form. I can see they made a comment under the post waring plagiarism is not acceptable. It looks like the comment was done manually - as they also replied to me a didn't fill in the form correctly. So I guess this is a manual processing of reports.
RE: Plagiarism on Hive: do we need a build in feature to stop copy-paste?