Why Link Aadhar card to voter card

According the news item appearing in Local daily Heraldo dated 28-05-2015 on page 10.  Aadhar not mandatory: EC

TEAM HERALD NEW DELHI: Trying to settle controversy over the decision to link the voter cards of the electors with the Aadhar number, the Election Commission has clarified that furnishing of the Aadhar number is only optional and not mandatory. It said: " No electoral service will be denied to any elector on the ground of non- furnishing of Aadhar number. In a letter to the chief electoral officers of all states and union territories, the EC said non- furnishing of Aadhar number will not be ground for deletion of name of an existing elector from the electoral roll. On its April directive to collect the Aadhar number from the electors during revision or updation of electoral rolls, the EC said it was only for authentication of details of the electors and nothing else. " Aadhar number of an elector shall not be displayed/ reflected in electoral rolls or EPIC or voter slips or shown in digitized form on website for public scrutiny or in any other document of the Commission, shareable with public or put in public domain. It must be ensured that Aadhar database is not misused under any condition," the EC added.