Post discussion threads: Hover over the comment you want to report and click on the little red flag that appears. Once three different people have flagged someone, this person will be contacted. Subsequent failure to comply once more with common rules of respect or decency will terminate their membership (the running month of Book Club membership is not reimbursed).
Community network: Use the Contact form to signal what you perceive as improper behavior. If the webmaster agrees with your judgment, the concerned person will be contacted (without mentioning your identity). Those twice at fault in the span of four weeks will have their membership terminated (the running month of Book Club membership is not reimbursed).
