Individuals who earned 5,000 yuan ($724) or more by illegally selling others' personal information will face up to three years behind bars, according to a judicial interpretation jointly issued by the Supreme People's Court and Supreme People's Procuratorate on Tuesday.

Those who illegally obtain, sell or provide 500 pieces of data related to personal credit or property information could face a prison term of up to seven years, the new rule stipulates.

The judicial interpretation, to take effect on June 1, is crucial to fighting the trafficking of personal data, and also a key way for the top court to combat telecom and online fraud, a senior judge said.

"Many telecom and online frauds are caused by personal information leaks or infringement. The interpretation will not only increase protection for personal data, but also fight fraud from the start," Li Ruiyi, deputy chief judge of the top court's No 3 Criminal Tribunal, told China Daily.

China revised the Criminal Law in 2015 and introduced a new crime called "infringement upon a citizen's personal information". The law stipulates "serious" violations are punishable by prison sentences of up to three years and "very serious" violations by up to seven years.

However, the law failed to specify what "personal information" was, or which circumstances would be considered "serious" or "very serious", making it difficult to enforce.

Now the judicial interpretation makes clear that not only residents' general information－such as names, addresses and identity card numbers－are considered "personal information", but also their travel information, mobile phone contents, transaction data, and credit and accommodation records.

The interpretation lists 10 circumstances that could be deemed "serious"－such as illegally obtaining, selling or providing more than 50 pieces of data related to personal credit or property information－and four circumstances listed as "very serious"－such as violations that lead to the victim's death, serious injury, mental disorder or kidnapping.

"Such specified and stricter rules will play a bigger role in deterring potential violators, thus better protecting people's personal data and privacy," Li said.

"What's more, it will help fight the rapid rise of telecom and online fraud, and serve as practical references for judges in court hearings," he said.

Chinese courts heard 1,726 cases of telecom and online fraud in 2016, up by 51.5 percent year-on-year, according to the top court. Li forecast that the number will continue rising sharply this year thanks to the country's crackdown on telecom fraud.

He said judges nationwide are also facing challenges in hearing such cases.

Some Chinese fraud suspects are based in foreign countries, which makes it harder for Chinese law enforcement officers to find them, let alone verify how much illegal profit they made, Li said.

Although Chinese authorities have ramped up international cooperation to combat such crimes, and the top court issued a guideline on telecom fraud at the end of last year, "such efforts are still insufficient," he said.

"As we're protecting privacy by issuing judicial interpretations, some departments with citizens' personal data, such as banks and telecom entities, should also take their responsibilities more seriously, including implementing real-name rules," he suggested.

In recent years, online fraud has caused great economic losses to residents, and even led to deaths.

In August, Xu Yuyu, an 18-year-old student in Linyi, Shandong province, was reported to have died of a heart attack after her personal data was released and she was cheated out of money meant to pay her tuition.

Court hearings in the case, which aroused wide public outrage last year, will start soon.