We all know that the anti-open troll Jeffrey Beall has burned all his karma, and rendered his purely subjective list of "predatory open-access journals" void of all value. DOAJ is doing stellar work on a whitelist of reputable OA journals; but do we still need a blacklist? Perhaps we do, if only as a foundation to studies like the one that Cenyu Shen presented this morning. So if we decide we do want a blacklist, how can we arrive at it? Reddit-like voting? Wikipedia-like editing? StackOverflow-like discussion? Who would own such a list? Who would stand behind it?