Google Scare - REally? $19 bill

A send key that was mistakenly punched and this is the reaction (PMT) in the stock exchange?
Why are the stock markets so sensitive. Analysts are creating fear amongst themselves, do they all sit in a room with blacked out windows winding each other up like jumpy horses. Google still in profit, forecasting is a skill best left to weather centres... low and behold they get it wrong too!
http://www.bbc.co.uk/news/business-19995730