Yahoo is set to start blocking access to mail accounts through third party sites, that is Facebook and Google. The company began the transition on Monday, by requiring Yahoo sign-ins for its Tourney Pick'Em for the NCAA basketball tournament later this month. Facebook and Google sign-in buttons will eventually be removed from Yahoo overall. As of now, almost all the websites have been using the same options to offer access to the users to its products. Removing it might just not help but there could be some other contingency plan that Yahoo must have cooked in their hood to replace if in case the removal of the options would fail. The company also believes that its services are quite attractive enough to make Facebook and Google users switch to Yahoo products. Also the Yahoo IDs might make users more likely to use other Yahoo services. Recently, Yahoo has also cleared all the Yahoo usernames which was abandoned by the users.