Her video, as well as a follow up video in which her father rages against her bullies, have been seen by millions. There is even a remix that blends her rants with a Justin Beiber song.
In the second video, as Jessi sobs in front of the camera, Gene Leonhardt warns viewers to leave his daughter alone.
"This is from her father. You bunch of lying, no good punks," he said, raging into the webcam. "And I know who it's coming from because I back traced it .And you've been reported to cyber police and the state police."
In an exclusive interview today with "Good Morning America" Gene Leonhardt said he was only trying to protect his little girl.
"As a father, I was just trying to support my daughter and get people to stop hating," Gene Leonhardt said.
Diane Leonhardt, said the entire experience has been frightening.
"When this first started, we were very afraid,' she said.
Cochran said it was unclear whether the phone calls and e-mails made to the Sheriff's Office were out of true concern for Jessi or whether they were made maliciously.
"If we had the evidence that someone has made a threat to a child in Marion County, we'll start pursuing suspects," he said.
Police also investigated and quickly dismissed other claims made to them that Gene Leonhardt was molesting his daughter, an accusation that made him cry.
Detectives, Cochran said, have released little information about such correspondence and what evidence they might have about where it all came from.
Jessi's social life has largely been confined to her computer. She told ABCNews.com that most of her friends are online.
"I don't really get along with people from school that much," she said. "They don't like me because they see me and they think I'm weird."
On Stickam, which has had its share of controversy over a proliferation of child pornography images, Jessi would chat back and forth with her cyber friends. She was also active on the teen gossip site Sticky Drama. It was there, she said, that her nightmare started when another user took a picture of Jessi and a friend at a concert off the photo-sharing site PhotoBucket and posted it along with the rape allegation.
But Jessi, whose account has since been removed at Stickam, insists she's not too young for this kind of activity.
"I think age doesn't really matter," she said. "It's the person -- him or herself ... and how they deal with that."
But she still is only 11. She likes music and can play a little bit of guitar. She dreams of a career styling hair and makeup -- and maybe learning how to do body piercings.
Jessi told "Good Morning America" that she was sent to a mental health facility when authorities believed she might be suicidal. She insisted that she wouldn't kill herself, but said she could understand how someone could be pushed over the edge.
"I think that's completely wrong that people would taunt people to some degree that they would actually kill themselves over it," she said. "And that's actually completely wrong and whoever is doing it should be locked away for a really long time."
Internet security expert Parry Aftab, founder of WiredSafety.org, agreed that this back and forth of online rants and cyberbullying should have been stopped before it ever got to the point where Jessi was receiving death threats.
"At some point we need to have an adult in charge," she told "Good Morning America." "Don't try to take it into your own hands."
At 11, Jessi isn't even old enough to use the social networking sites where the cyberbullying took place and where she posted her videos, Aftab noted.
But family therapist Terry Real said that Jessi's retaliation video deserves attention by itself.
"This is about violence breeding violence," he said.
"It's great that this kid is getting some counseling," Real said. "This is a trauma and it needs to be taken seriously."