It has become a common phenomenon that people kept the money they picked up without telling others, but it shall be done with some technical content, otherwise in this era of rampant high technology, you may fall into a trap unconsciously. Recently it was reported on the Internet that a female student in Nanjing picked up an iPhone 4S by chance during the New Year holiday. She did not think of returning it to the loser and took a lot of self-portraits with the phone. Within a few days, she took as many as 313 photos which were all saved in the mobile phone.