In order to implement the personal information protection law, private information will not be leaked. Generally speaking, if you want to handle some financial business, the bank will ask you to provide personal information such as ID number and mobile phone number. In order to protect your personal information, the bank will ask you to write down your personal information on white paper, so that your personal information will not be leaked. In addition, when an account is stolen, it is often by obtaining personal information such as the user's ID number and mobile phone number. If you write your personal information on white paper, you can effectively prevent the account from being stolen.