A lot of parents worry that their children are spending too much in front of phones and tablets. Parents in Taiwan are now legally obliged to do something about it, though the parameters of the rule are unclear.

Lawmakers have expanded existing legislation to say that children under 18 on the island "may not constantly use electronic products for a period of time that is not reasonable." The law now equates spending excess time on electronic devices to other, more commonly accepted vices, such as smoking, drinking, drugs, watching sexual or violent imagery, and chewing betel nuts.

Parents who expose their kids to electronic devices to the point that they become "physically or mentally" ill are liable for a $1,600 fine. But the law doesn’t say exactly how much time is unreasonable, which will no doubt complicate enforcement.

The American Academy of Pediatrics, which recommends a maximum of two hours a day of screen time for kids, found in a recent study that 8-year-olds in the U.S. spend an average of eight hours a day with some form of media—and many child-development psychologists urge more unstructured play time. In addition, another factor the Taiwan law fails to cover is the fact that many parents are themselves always connected, which can also undermine children's well-being.