DUBAI // Doris Lopez was shocked to stumble upon a Facebook conversation between her 12-year-old son and some of his classmates that resulted in name-calling.
As a result, she talked to him and persuaded him to leave the site until he was old enough to use it.
While in theory Facebook requires users to be over 13, the verification process is easily deceived.
According to a study released last month by the US magazine Consumer Reports, about 7.5 million Facebook users in that country were younger than 13. Of them, five million were 10 or younger.
"Facebook itself is not unsafe but it can be potentially unsafe depending on the way you use it," said Chris Moore, general manager of Trend Micro, Middle East and Africa, an internet safety consultant firm.
Children, he said, can be more vulnerable in the virtual world and might give out more details than they intend to, as they are more trusting.
He also warns parents to be on guard about the various malware that their computer may get through some of the games children play on Facebook.
Five-year-old Mohammed Radi wanted a Facebook account after he saw the games available through it.
His 21-year-old sister, Dana Radi, signed up for him using one of her email addresses.
"We are not very worried about him as he only plays games on them and there is always somebody there with him when he is online," she said. Ms Radi says her brother does not know how to use the other functions of Facebook.
Jo Darnell, 45, said the internet can be a weapon if it is used unwisely. Her 10-year-old daughter, Meghan, is not allowed a Facebook account, while her two older brothers Christopher, 16, and Will, 13, are on it.
"My daughter may be too young to know all the dangers and may give out too many details unintentionally without knowing the dangers behind it," she said.
Mr Moore urged parents who let children use Facebook to "be an expert in the security settings of the social networking sites and train their children to be an expert, too."
Underage users are generally supervised by parents or older siblings. When Mrs Lopez's son got an account, she made him add her as a friend, so she could monitor his activities.
Mrs Darnell goes a step further, when she says that her sons are being monitored by her husband even though they are old enough.
"We can't stop them as it is what others are doing but we can monitor them at least," she said. She knows many parents, though, who leave their children unmonitored while using the internet.
There are dangers for the future, too. "Children often fail to realise that whatever they post online would be always there and would be visible to their future employers when they go for a job interview," Mr Moore said. "That can be quite embarrassing."