Damages for "sexting" have been awarded for the first time, the BBC has learnt.
The legal precedent was set in a case where a girl was encouraged to text sexually-explicit photographs of herself to a teacher.
It means anyone manipulated into sending or receiving a sexually-explicit message or image, and who suffers psychological harm as a result, can now bring a claim for compensation.
The NSPCC said awards of damages were important but risked being misused.
The BBC has spoken to the victim in the case, who cannot be named for legal reasons.
When she was a teenager, she developed a friendship with a teacher at The New School - an independent special needs school near Sevenoaks in Kent.
William Whillock was the vice-principal and child protection officer at the school and in his mid-50s at the time.
"He was like a father figure to me," the victim said. "He always said that if there were any problems, 'Just give me a call.'
"When I was at school I used to go to his office and talk to him about problems at home. As the relationship built up, things just got worse."
Mr Whillock would call and text her late at night requesting naked images.
On one occasion, she provided a photo of her genitals and said: "Here's wat u ordered."
Mr Whillock replied: "That's so lovely. Meanwhile you can use your imagination to send me some more when you want."
After she sent another picture of herself topless, he texted back: "mmmmm x".
Speaking to the BBC, she said: "I used to feel that I was pressurised into sending them. I used to think to myself, just forget about it, it's nothing."
By Clive Coleman, BBC legal correspondent
The victim's civil action for damages was based on a claim that the encouragement by Whillock of the exchange of text messages and images would inevitably cause her psychological harm.
Although the texts and images themselves were not directly intended to cause her harm, the court found there are some consequences of conduct that are so obvious "the perpetrator cannot realistically say that the consequences were unintended".
And it was obvious in this case that the illicit relationship would eventually cause nothing but harm to a vulnerable young woman.
This means that anyone involved in sexting another person needs to be sure that person is psychologically robust, is not vulnerable and is consenting to the exchange of messages and images.
During a year 18 text messages were exchanged. Twenty photographs were sent to Mr Whillock, 12 of which featured the victim either topless, in her underwear or naked in the bath and three were even more graphic.
Although he told her to delete the photographs and texts, her phone was discovered by another teacher at the school.
Mr Whillock was arrested in front of pupils and staff and pleaded guilty to possessing indecent photographs of a child in court.
He denied that he encouraged her to send him indecent photographs and that he was attracted to her. The judge in the case, Sir Robert Nelson, found him to be a "wholly untrustworthy witness". Mr Whillock received a three-year community sentence.
The victim sued for the harm done by him and the case went to trial. In September, a judge awarded £25,000 to the victim for the harm caused by the text messages and images alone.
"This is ground-breaking law," said David McClenaghan, a lawyer at Bolt Burdon Kemp who specialises in child abuse cases. "We know that adults who manipulate children into 'sexting' can be prosecuted.
"This case establishes that anybody who is manipulated into sending or receiving sexually-explicit text messages or images - we call it 'sexting' - and then goes on to suffer harm, could bring a claim for compensation.
"We now have apps such as Snapchat and WhatsApp and it's a very regular occurrence for people, children, to be exchanging sexually-explicit images. The scale of these cases is potentially enormous."
The NSPCC said: "It's vital that there are serious punishments that deter offenders from committing these crimes against young people.
"However, whilst damages could help discourage potential abusers, there is a danger that young people could just use this as a way to get cash by suing one another.
"It's important for victims to get justice.
"But it's equally important to educate children about not sharing this kind of explicit material."
The victim, now in her twenties, said the harm done to her was serious and long-lasting.
"It affects my relationships," she said. "I felt I was forced into it.
"Whenever I have a relationship it's always stuck in my head. I feel like they're going to abuse me again."