Mother sobs in Adelaide court as son jailed for sex offences

A mother has sobbed in an Adelaide court as her son was jailed for sex offences.

The woman lowered her head and wept as a judge ruled her son, Phillip Charles Smith, 24, of Happy Valley would spend at least 18 months in prison.

When Smith was 21, back in 2012, he chatted online to four girls aged between 13 and 16, offering them up to $200 for sex.

He also offered them alcohol, cigarettes and mobile phone credit if they supplied him with semi-naked pictures.

Police found video files on Smith's computer hard drive of children under 14 having sex.

District Court Judge Wayne Chivell said the young man had groomed immature and vulnerable girls.

"Any objective reading of the conversations you had with these girls can only be to the conclusion that you were grooming," he said.

"In my opinion, your behaviour was sexually predatory.

"It is one thing to be an introverted person who resorts to the internet because he or she has difficulty maintaining relationships with people in a normal social context. It is another thing entirely for that person to use the internet as a means of exploiting children."

Judge Chivell said the three-year sentence he imposed had to deter others from such offending.

"Children must be protected from their own immaturity and lack of judgment about the long-term effects of their behaviour," he said.

"The internet has created the ability to cause great harm to vulnerable people.

"Many people do not realise how prevalent the offence of possession of child pornography is - it represents a worldwide problem."