A scene from the latest movie version of Boonie Bears.

Lu has classified current made-for-children TV content in China, cartoons especially, into five categories.

According to that standard, popular works such as Boonie Bears and Balala The Fairies are both rated TV-PG, meaning they aren't appropriate for children under the age of 10. Weslie, watched by millions of children probably even before they start to talk, turned out to be only appropriate for children of at least age 7.

While working out the criteria to measure the contents, Lu says her team specifically tried to talk about the influence of violence, by the length of scenes showing "inappropriate action". Being frequently exposed to violent scenes will cause children to become less sensitive to such acts, Lu says.

This may increase their chances to tolerate it and therefore lead to a lack of awareness in self-protection. Not to mention there's also a chance that children will become violent themselves because they tend to imitate the characters they see on TV and films. She points to the trend of children using bad language in schools and among peers as a fallout from watching such cartoons.

Other than violence, scenes about sexual behavior can confuse or mislead children.

"All this is because content providers in China lack the basic knowledge of child development, and also a sense of responsibility. They never think for the children and only work for the market," Lu says. "There has to be someone who can point out the seriousness here."