Generally, for KYC verification at banks, either customer has to visit the bank branch or bank executive visit the customer for paperwork. But, Bitcoin exchanges in India are verifying customers online. I wonder HOW?

User's Photo, Aadhar No. (with scanned copy of Aadhar card), PAN No. (with scanned copy of PAN card), Mobile No. (verified with SMS/Call) and Bank A/C No. are taken. But, how is it verified that the given Photo, Aadhar No. & PAN No. correspond to the given Mobile No. & Bank A/C No.?

What I meant to say is can not identity theft be an issue to these exchanges?