To provide a bag snatching prevention machine with a built-in GPS as a crime prevention item having a function of preventing bag snatching by simply changing a program configuration of a mobile phone with a built-in GPS in order to eliminate damage caused by bag snatching.

The speed of a pedestrian is around 5 km/h in average and around 20 km/h when running. Therefore, bag snatching can be easily prevented by putting in a bag or the like a bag snatching preventing machine which uses a device with a built-in GPS and is optionally set so as to ring an alarm buzzer when for example its speed is or higher than 30 km/h.