Social moods and events, causes and  effects, stock markets, Prechter, etc:
http://www.socialmoodconference.com/robert-prechter-at-the-2012-social-mood-conference-the-elections-paper/

Here comes the crux of the matter:

Social mood/sentiment swings from low to high to low etc.
In other words, social mood has cycles.
And somehow by hook or by crook that mood has been found to have a big impact on how people invest in stock market.
So it could be used to gague the stock market sentiment, thus making it a useful or even powerful technical tool when making a buy/sell decision.