We know they've existed in the past (such as the voting ring around The Atlantic), so are you asking if we've succeeded in catching them all? I highly doubt it.
Personally my motivation isn't just to improve the front page, but just to do this in the interest of science. We probably have one of the best communities on the internet insofar as percentage of members interested in data science. Providing this data would probably result in several HN worthy write ups on how someone went around detecting voting rings from the data made available.
Science should be a good enough reason to do it ;)
