A Gateshead man has been jailed for two years after promising to teach a 14-year-old girl to "kiss and make love".
Ian Williams, who is unemployed, thought he had been chatting to a nervous, virgin schoolgirl online - but instead, he was sending explicit messages and pictures to Dark Justice.
The group of paedophile hunters confronted 36-year-old Williams in Newcastle city centre with a camera, as he arrived to meet up with who he thought was the young teenager.
He was later arrested by police, who were armed with a stash of evidence gathered by the group.
Williams, of Wallace Street, Dunston, Gateshead, pleaded guilty to attempting to meet a child after grooming.
As well as being jailed for two years, he has been ordered to sign the sex offenders register for 10 years and told to abide by a sexual offences prevention order for life.
Speaking at Newcastle Crown Court, Mr Recorder Ewan Duff said: "You were making it clear you wanted to meet her to have sexual intercourse with her.
"From the very beginning you knew perfectly well your belief was that this was a 14-year-old girl who you were intending to have sexual intercourse with.
"This was someone posing as a girl, unbeknown to you."
Bob Spragg, prosecuting, told the court that Williams had started chatting to the teen on a social media site and they soon swapped numbers so they could communicate in private over Whatsapp.
During their conversations, Williams told the girl not to say anything about their meeting as "I could get called a paedo".
Williams reassured the girl he would teach her how to kiss and how to make love and said just before their meeting: "Do you realise, you will not be a virgin any more after tomorrow?"
He told the girl to wear "something sexy" for their meeting then joked that her clothing would not be on for long.
He told her in one message: "I can't wait to take your virginity."
When Williams was arrested he initially claimed someone had stolen his phone and must be responsible for the conversations conducted on it. He later confessed they were his own "stupid" actions.
Michael Hodson, defending, said Williams was "naïve" and has never done anything similar, before or since.
Williams will work towards rehabilitation and has become an "isolated person", Mr Hodson added.