The state of Indiana considers Zach Anderson a sex offender.

He doesn't. Neither do his parents. And neither does his alleged victim or her mother. But their opinion doesn't matter. The authorities are putting him on a sex offender registry anyway.

That's because the 19-year-old is serving a sentence for having sex with a girl who was 14 at the time. He didn't know that. She told him she was 17 -- and later admitted it in court.

Mr. Anderson's parents are fighting to get their son taken off the registry. But that's not going to happen before his release from jail, after serving his 90-day sentence, on Thursday.

"One thing we know for sure, [his life] is not going to be the same as before he went in," his father, Les Anderson, tells As It Happens guest host Susan Bonner.

Zach will not be able to touch a computer for the next five years or have internet access. That means he can't continue his college program. He won't be able to live anywhere with internet access or smartphones. He can't go near schools or public spaces. And he cannot live with a minor.

That means he can no longer live with his family. His parents' house is near a public boat launch, which is considered a park. And his younger brother is 15.

All this is because Zach hooked up with a girl he met on the dating app Hot or Not. According to his father, there are age restrictions on the app. And, he adds, his son asked the girl several times her age and she said she was 17.

About a week later, she contacted Zach and told him they were in trouble -- and confessed that she was really 14. Not long after, the police came to visit him.

He pleaded guilty to fourth-degree criminal sexual conduct, but his family tried to convince the judge hearing the case, Dennis M. Willey, to keep him off the sex offender registry. They even had the support of the girl and her mother.

"[The mother] came up to us [at the court] and she started crying and she said, 'I am so sorry for what has happened here,' and she walked up to my son and gave him a hug and then she knelt down and held his hand and prayed for him," says Anderson.

Both the mother and daughter made statements in court asking for leniency for Zach. But their plea fell on deaf ears.

As the judge sentenced the teenager, he said to him, "You went online, to use a fisherman's expression, trolling for women to meet and have sex with. That seems to be part of our culture now. Meet, hook up, have sex, sayonara. Totally inappropriate behaviour. There is no excuse for this whatsoever."

The family is fighting the ruling in court. But in the meantime, Zach will have to be careful once he is released on Thursday. If he violates any of the sex offender restrictions, he could end up back in jail.

"We've taught our boys not to have sex before marriage and the importance of waiting," says Anderson. "There is a difference between a moral failure and a legal failure."