Add the ability to mark a reviewer as a review bomber by flagging particular ratings and/ or reviews.

This could then lead to sanctions within the site such as not having those ratings count in averages and being hidden from the overall site, or potentially even more socially-oriented sanctions such as a "negative flair" marking them at a profile level.

The actual consequences are more fluid in my mind, as long as there are some, and having this ability seems like it would set HC apart from the competition in a very good way.