Yahoo patents granted on 21 December 2010

4 US patents granted on 21 December 2010 and assigned to Yahoo

1 7,856,477 Method and system for image verification to prevent messaging abuse
2 7,856,441 Search systems and methods using enhanced contextual queries
3 7,856,433 Dynamic bid pricing for sponsored search
4 7,856,384 Systems and methods for providing security in international money exchanges