Just today I was investigating a large number of messages in our queue, and I meant to click "View Emails" but right next to that button is "Delete Emails" and yes... I clicked it by accident. Immediately, it started to delete all mails in the queue, because CMQ has "All Emails" + "Frozen' + 'Bounce' + 'All Other' checked by DEFAULT... thus, with just one click, you delete your entire queue.
Either adding a "This will delete XX messages in the queue. Are you sure?" prompt would really be great!!