Last week, a Chinese woman was allegedly raped by a man in Shanghai after he invited her to his home for a "job interview" via WeChat, a text and voice messaging service developed by Tencent Technology Co.

The woman claims that once in the flat, she was offered a drink and then quickly passed out. She later told police she realized she had been raped after waking up. The suspect is currently being questioned by police.

The incident highlights serious privacy and security risks associated with WeChat and other social networking applications on smartphones. As most people have their WeChat accounts bound to their phone number, their profiles can be seen when a person searches for their phone number in WeChat.

Last year saw an increasing number of crimes related to the various social networking functions of WeChat. In Shanghai, a middle-aged woman had a one-night stand with a man she met on WeChat, and who then stole her iPhone and handbag.

In Guangdong Province, a 17-year-old girl was gang raped by nine people during a meeting with a WeChat friend. In another city in Guangdong, a man befriended more than 160 boys on WeChat and persuaded at least three of them to have sex with him. It seems that WeChat has become a hotbed of criminal behavior.

Dangers lurk, of course, in any form of contact with strangers, and many such crimes can also happen on instant messenger services like QQ and online dating sites, so I don't think we can particularly single WeChat out in this regard. But I do suggest that citizens be cautious of WeChat's distinctive location-based services which can be very dangerous if used in the wrong hands.

WeChat's "Look Around" add on, for example, allows you to see a list of other WeChat nearby users so that you can ask them to become your WeChat friends. The list of people is arranged from nearest to furthest and even details how close each of these WeChat users is to you. This naturally makes it easy for someone to stalk another person.

Another feature, "Shake," also allows people nearby to identify your exact location, as long as you shake your mobile phone at the same time they do.

While these features are not automatically turned on, and require the user to activate them by default, careless users may forget to turn the feature off once they've used it.

If the crime rates on WeChat continue to rise, I would suggest that WeChat should build safeguards into these apps to warn users of their possible risks. Parents, too, need to be aware of what kinds of apps and social services their own children are using.