来自于一个美国网友的经验

　　If you are ever forced by a thief or someone to take money out of an ATM machine, enter your pin number reversed. So if your number is 1254 put in 4521. The ATM machine will give you your money, but will automatically recognize this as a plea for help and will alert the police unknown to the thief. This option is in all ATM machines, but not many people know this.

　　在美国，如果你被一个强盗或者其他人胁迫着，要求你输入密码，从ATM机上取钱给他。如果你的密码是1254，那么就请输入4521。ATM机会将钱给你，但是同时知道了这是一个求救的信号。ATM机会在强盗不知情的情况下报警。这个功能在所有的ATM机上都有，但是并不是所有的人都知道。