Judges have called for female university students to enhance their security awareness and have suggested that they refrain from disclosing personal information online.
The judges' appeal comes after several young women were murdered or disappeared in recent months.
On Tuesday, China's top court revealed seven cases in which women and girls were defrauded, kidnapped, raped or killed after they met Internet friends. The court wants to warn more people not to easily trust strangers or those they meet in cyberspace.
"All convicts in these cases took advantage of the Internet, making use of the trust established online to commit their crimes," said Yan Maokun, deputy chief judge of the Criminal Department at the Supreme People's Court.
Yan said the number of such cases has risen since the introduction of instant messaging tools such as QQ and WeChat.
Three defendants in the seven cases were sentenced to death for kidnapping, rape and murder.
In June 2013, Xiao Kechen, from Foshan in Guangdong province, was imprisoned for 14 years for raping a 15-year-old girl he met through WeChat and robbing her of 20,000 yuan (S$4,152) and a cellphone.
"Victims have little awareness of self-protection and easily trust strangers on popular instant messaging tools," Yan said.
Ran Rong, another judge in the department, suggested that women and girls keep in touch with their families or friends when they go out alone or in emergencies.
Ran, whose daughter is a university student, said they should also not disclose personal information.
She added, "We should take advantage of these instant messaging tools instead of being taken advantage of.
"A young woman can take a picture of a taxi license plate and send it back to her parents via WeChat if she has to go out alone, or map apps can be used to check whether the driver is taking the right route."
Wang Leilei, a prosecutor in Beijing's Dongcheng district, said the most important thing is to tell female students how to protect themselves when they are in danger.
"After all, we cannot stop young people from using smartphones or making friends online. But we can teach them how to refuse the advances of strangers," she said.