In order to track hackers, the agent sent a warrant to AT & T to submit all the call records of the day the hacker placed control of the investor's mobile phone number. According to the records provided by AT & T, it turned out that this number was used from Samsung mobile phones. When I asked investors, I heard that Samsung mobile phones did not remember at all, and this cell phone declared a hacker's phone and identified the mobile phone's identification number ( IMEI ). And when the police sent a warrant to AT & T to check the phone number that the same IMEI mobile phone was sending, about 40 cases were detected