Yahoo patent applications published on 14 February 2013

5 US patent applications published on 14 February 2013 and assigned to Yahoo

1 20130042311 MULTI-STEP CAPTCHA WITH SERIAL TIME-CONSUMING DECRYPTION OF PUZZLES
2 20130042180 METHOD AND SYSTEM FOR PROVIDING MAP INTERACTIVITY FOR A VISUALLY-IMPAIRED USER
3 20130041765 METHOD AND SYSTEM FOR OPTIMUM PLACEMENT OF ADVERTISEMENTS ON A WEBPAGE
4 20130041757 DISAGGREGATION TO ISOLATE USERS FOR AD TARGETING
5 20130040612 METHOD AND SYSTEM FOR GROUP COMMUNICATION ACROSS ELECTRONIC MAIL USERS AND FEATURE PHONE USERS