So please be aware.
DO NOT LEND YOUR HANDPHONE TO STRANGERS.
These con artists who will approach you are likely to be a female or an elderly person. They will tell you that they just got rob and need to call the police. Right in front of you, they will call 110, 911 or 119 (the emergency tel for the local police). They will speak loudly for you to hear that they are reporting a case but halfway through, they will pretend that the reception is poor and walk about 5meters away from you with their back towards you. All they need is 1min and a tiny gadget that acts as a USB (available for sale in China) to copy your entire phone book contacts.
Then over the next few hours, they will SMS to all your contacts, pretending to be you (with your tel no appearing in your contact's phone). The SMS will say that you are now overseas, in trouble with the police, you cannot use your phone and that is why you are sending out SMS. You need help to transfer money to an account. Usually the amount they ask is within affordable range. Your phone will not be contactable for the few hours that they are busy sending out SMS.
So your family and friends will believe you are in trouble. The case below happened to a Taiwanese and he reported to the local police a few days later when his friends finally manage to contact him and he learned that he was being duped. The police told him that this is an old trick that they use to target tourists and now they are moving to the locals. So my friends, please do not lend your phone to ANYONE you do not know. If they really want help, send them to the nearest police station!