A few days ago, I was having a meal with one of my favorite teachers from the local primary school. We were talking about life in Shanghai in general, where to get organic food, where the good supermarkets are, and where to get imported food products. Our conversation soon segued to how there had been so much petty fraud recently via random phone calls and text messages. She suddenly gave me a word of caution and said, "You must be careful with Hotmail and other group networking sites." One teacher's email was hacked into and IMS messages were sent to all the parents of her students in the class asking them to top up her phone card with 1000RMB.

She then mentioned that this teacher's reputation was ruined by the time the scam was finally uncovered.

My jaw dropped when I heard this. I asked her, "Would a parent take that kind of request seriously?"

She replied that some might and send the money, but others who couldn't spare 1,000 RMB might offer less – maybe 200-300RMB.

I was astonished. I knew that if I had received a text message like that, I would have assumed that it was a fraud or a joke. I later asked my husband about it. He replied, "Look, for a scam to work, there has to be a volume of people for whom it is a reasonable and even a predictable request. So obviously this kind of request from a teacher to a parent is not unusual."

I nodded and thought about it. The idea aroused my curiosity. The very next day, when I was having lunch with a few of my Shanghai girlfriends, I mentioned this story to get their reaction. So you can imagine my surprise when one of them admitted that she had recently filled up the phone card of her son's teacher.

I was flabbergasted and asked her how she knew to do it. The friend answered that she often sent transportation or shopping cards worth several hundred RMB as a gift to this particular teacher, and one day the teacher asked her to put in 500RMB on her phone card.

I couldn't believe what I was hearing. It was virtually the same exact words I heard from the scam. I then asked my friend whether she complied. She replied, "Of course I did it! How could I not?"

She then muttered, "I'm telling you, the atmosphere at Chinese schools is not good. This is not unusual. It's like this everywhere."

I wasn't sure what to think. Should I feel sorry for the parents who had lost 1,000RMB filling up the phone card of a teacher whose email was hacked? Or should I feel sorry for the teacher whose reputation was ruined because of the hacking? Or should I feel appalled at the teacher who made such a bold request from my friend?

Being new to the art of scams, I wondered about this topping-up of the phone card. My mobile phone bill rarely goes over 100RMB a month; how much money can any one person really spend on a mobile phone service? Can the money on the phone card be redeemed for cash or other things? Or is there a rotation of family members with smartphones who can all benefit from having the phone card topped up by 1000RMB every few months?

It was yet another occasion where I felt glad that I was a foreigner in China. I felt very fortunate that I had never been asked to top up any teacher's phone card or received any other uncomfortable requests.

But after the I heard these stories, I started to look at the world around me in a different light. I became more suspicious. Every time someone pulls out an expensive mobile phone, I can't help but think: who is really paying the bill?