The next time someone asks you for your cellphone number, you may want to think twice about giving it.The cellphone number is more than just a bunch of digits. It is increasingly used as a link to private information maintained by all sorts of companies, including money lenders and social networks. It can be used to monitor and predict what you buy, look for online or even watch on television.
http://www.nytimes.com/2016/11/13/business/cellphone-number-social-security-number-10-digit-key-code-to-private-life.html