Speaking of China, there's an advertising scam daily here where you get a phone call, usually a single ring that you miss or don't even hear and of course your phone has a 'missed call'. Happens about 4 or 5 times every day (and I mean a 24 hour day).
Many people will ring the number back and it's a bloody recorded advertising message that's just cost you a call and them nothing.
I am less than amused when this happens in the middle of the night when I'm asleep, I don't ring the number back of course but I check the phone to make sure it wasn't family.