Maybe the better metric is usefulness to the reader. A suitable algorithm can recognize things like "N.N. smells", but so can any user. The current algorithms are very effective at dealing with "XY is gay" and "Buy herbal viagra"; you don't see much of that.

The really insidious stuff is spin doctors for companies and nations. So far, Wikipedia does a very poor job with geopolitical conflicts, and competing financial interests are not taken seriously enough either.