At press time Google's stock has dropped as much as $16.72 (4.34%).
The reason for the drop is unclear at the moment but since two weeks ago Google's shares have gradually been falling down. Some of the reasons for the drops are:
The search engine helped the Chinese government to censor search engine results. Google denied to hand over search engine data to the U.S. government. Allegedly copyright infringement with the Google News and Google Book services. The company's earnings were lower than Wall Street analysts anticipated.