These days parents in China face a new challenge trying to protect their kids from porn, but not just on then internet, on mobile phones too.

More than 50-million primary and high school students cell phones and almost all have SIM cards that can access the internet. It's a combination that makes it extremely difficult to censor children's acess to harmful media. Ren Ting takes a look at the efforts being made.

One can buy a SIM card in newspaper booths like this one. There are hundreds in a city like Beijing.

This salesman says all the SIM cards have access to the Internet. No application or registration is needed.

The function itself does no harm, but hundreds of porn websites make it a great threat to millions of teenage cell phone users.

Lawyer Tang Hongxin said, "In law, they are individuals with no civil capacity or having limited civil capacity. They can be easily tempted and indulge in harmful messages like porn, violence and evil religions. The outcome could be unexpected and in a bad way, if we have no restrictions on Internet services to minors with cell phone."

Legal experts advise government regulators to learn from Japan, which has the same problem.

Lawyer Tang Hongxin said, "Japan has recently issued a regulation on this issue. Internet services to minors cell phones are cut off between ten p.m. and six a.m the next day. And access to harmful websites will be stopped within a 24-hour supervision system."

Some phone operators, including industry giant China Mobile, are blamed for spreading pornography via the Internet on phones.

On some websites, there are connections to some China Mobile services, such as the download of cell phone video or games. The more popular porn websites become, the more revenue they will bring to China Mobile.

Porn websitee founder Sheng Xisong said, "The two biggest beneficiaries are the advertiser and China Mobile. I'm the third."

Dr. Li Qigang, China Academy of Social Sciences,said, "We have done a sample survey. It shows on 167 porn websites, China Mobile has business promotions on 41 of them."

China already has some laws and regulations on Internet services to minors. But as access becomes more convenient and easier, the Internet service provided via cell phones lacks such protection.