Gmail and Yahoo are providing online mail services to millions of internet users across the world. Though it was useful for the many, some of them were misusing these mails for the antisocial activities.
It was proved many times and the cops are identified the culprits, who misuse the mail services. However it is becoming a challenge for the cops in all the countries to find the culprits, who use the fake mail ID accounts. To overcome this problem, investigation agencies from many of the countries requested mail providers to make mandatory of some credential information such as address and mobile number.
After the repeating requests from the investigation agencies of many countries, Yahoo and Gmail (major e mail service providers) decided to make mobile number mandatory for creating E mails. After making mobile number as mandatory for new E mails, same process will be implemented for the existing E mail user it seems.