Prosecutors and judges in Beijing have urged people to pay more attention to the potential for crimes to be committed utilizing WeChat, a popular social network app.

The app, which has a popular function that shows the user's position, boasts 400 million users at home.

So far, nearly 50 cases of crimes where suspects have made contact via WeChat have been reported around the country.

Rapes account for the majority of them, Beijing based newspaper The Mirror reported.

Chaoyang District People's Court, which deals with the most such cases, said it has become common to see defendants in theft, robbery and rape cases in the area have used the app to contact strangers.

A 34-year-old man named Wan was accused of raping a woman who traveled to the capital in September after he contacted her via WeChat, said Wang Pu, a prosecutor in Chaoyang district.

A man named Wang, who is suspected of stealing about 10,000 yuan ($1,630) from prostitutes in two cases after contacting them via the app, was arrested on June 14, said Qi Yamei, another prosecutor from the district.

The app can easily locate nearby users who have turned on its global positioning system.

Li Jiali, a judge at the court, said the function makes it easier for criminals to locate potential victims and has great risks. She suggested smartphone users dismiss stranger's online requests and be careful when using the system.