The first kind of address book friends "betrayal": the card will be required to fill in the emergency contact, many APP will require authorization address book and so on. The second kind of information through the ID card to find your new number: in the process of cell phone number, the operator will require the use of ID card real name, when you apply for a new cell phone, you will leave their ID card information, the collection company is the use of this information, so as to be able to get to your new cell phone number. The third clock social security information: there are also many users who apply for cards or loans offline, will fill in the social security, provident fund account and other information, once you change a new job, the other side through your current social security payment unit, is able to find you.

Nowadays, a lot of information of the user is platform **** enjoy, it will leave some information, for example, when you buy something online, naturally, you will leave a new cell phone number, so this kind of time collection will be able to get your new cell phone number through the big data combing. In general, from the beginning of the application, the user agreed to a variety of authorizations, informed the account number, etc. are the information "leaked" to the other side, the collection wants to look for if there are traces to follow. Currently is the era of big data, generally want to get any information about you, as long as the creditor wants to get, then it is not a big problem. Every app in your phone can get your information, and creditors will cooperate with third-party big data companies, so avoiding is not advisable.