Members should have an option to do a "super thumbs down" on a limited basis, just like vacation days. Maybe five super thumbs down a year?
The Super Thumbs Down could be bolded, or brightly colored, or have a special icon, or maybe even, with a "second" by some other member, shut down or freeze the thread?
Maybe it would also be a paid subscriber only feature?
If anyone objects to the prop, how about a one-time a year option? Something that would really count?