investigation into a new kind of scam, one that preys on the kindness of strangers, not just any strangers but good hearted celebrities. Abc news tracked down a woman behind an elaborate trick. Here's... See More
investigation into a new kind of scam, one that preys on the kindness of strangers, not just any strangers but good hearted celebrities. Abc news tracked down a woman behind an elaborate trick. Here's abc's david wright. Reporter: Brad paisley wrote a hit single on the perils of on-line relationships. ♪ I work down in the pizza hut i drive an old hyundai ♪ Reporter: In the music video, jason alexander plays a sci-fi nerd who pretends online to be paisley. ♪ Cause I'm so much cooler online ♪ Reporter: Now paisley and his wife actress kimberley williams paisley are opening up about how they were the victims of a real online hoax by a woman claiming her daughter was dying of cancer. She was supposedly 8 years old and had neuroblass toem ma and it sounded very sort of real. And I though, I would love to just talk to her and say hi. Reporter: Talk they did. By phone, email and text. And then it started getting weird. Hi, my kim. I just wanted to say thank you for letting me love you. Reporter: The caller tugged at their heartstrings, but never asked for money. At one point, brad got on the phone and sang "amazing grace." Then the sob story suddenly unravelled. I felt so violated, and scared. I vowed that night I'm going to find her. Reporter: Turns out, the hoaxer had done this for years, to other celebrities, using photos and stories of real kids who had died of cancer. We finally found her -- you're hope jackson. -- In a trailer park in douglas, wyoming. Hope jackson knows what she was doing was wrong but believed she wasn't breaking any laws. I never asked for anything from them ever. Reporter: Psychiatrist marrc feldman believes she suffers from a mental illness he calls "munchausen by internet." The internet has made this blow up. Reporter: But jackson made one big mistake that put her behind bars. "Amazing grace." Turns out it was worth a lot. The performace itself has value? It does. Reporter: Even if you're just singing it over the phone? Right. Reporter: So this was al capone being caught for tax evasion. It really, really was, yeah. Reporter: The charge, theft of services. Because it's brad paisley singing, the performance was worth more than $5,000. That made it a felony. Hope jackson pled guilty and went to jail. Much more on your story tonight on "nightline."
This transcript has been automatically generated and may not be 100% accurate.