Former Blue Peter presenter Richard Bacon has revealed how he has been targeted by abusive internet "trolls", in a bid to highlight the growing problem of cyber bullying.
Bacon, now a BBC Radio Five Live presenter, has suffered nearly two years of anonymous online abuse directed not only at him, but also his wife and baby son.
The experience has prompted the 36-year-old to make a complaint to the police, he said.
The presenter has also tried to turn the tables on the trolls and highlight the issue of internet bullying.
In a documentary, The Anti-Social Network, to be screened on BBC Three on Monday night, Bacon tried to track down his abuser and also met bereaved relatives left distraught after they were preyed on by "RIP Trolls" posting offensive messages on tribute sites.
"It's definitely growing and it's definitely getting worse," he said.
"You have got to try and work out where critical comment crosses over into harassment.
"Under freedom of speech people can criticise you and slag you off, it's their right to do that. It's when it becomes deeply personal, obsessive and weird."
He said the line was crossed for him when criticism of his radio show turned into abuse involving his mother and wife, as well as his five-month old son Arthur.
Bacon originally wanted to try to meet the troll who was targeting him, but had been advised to take it to the police.
"I wanted to know how a dislike of a radio station could go to contacting my family and tweeting about my baby," he said.
"But the advice I got from a psychologist and a police officer was to make an official complaint, so I'm in the process right now of making a complaint to the police."
During the programme Bacon met families who had been targeted by trolls, in cases he said were far more distressing than what he had been through.
"What I have been through isn't that bad really, it's been distressing for my family but personally as a broadcaster it's something I know how to deal with.
"What's really heartbreaking is the parents and families of people who have killed themselves."
He met the parents of Tom Mullaney, 15, from Bournville, Birmingham, who apparently killed himself after being bullied online.
A tribute site for him was hit by trolls, leaving vulgar messages that were seen by his family and friends.
"They see these nice tributes then they also see these weird sexual, violent comment and imagery," he said.
"For people who don't even understand Facebook in the first place, as well as being upsetting and prolonging their grief, it's confusing."
During the documentary, he also met a self-appointed "troll hunter", who tries to track the people down and expose them.
"What he does is he works out who they are then posts letters to their neighbours saying, 'do you know your neighbour is doing this?'
He said the "troll hunter" told him perpetrators had started hacking other people's accounts and sending offensive messages from their identities, which could lead to retaliation.
"Imagine if you're the brother of the person who has killed themselves and you see the name and picture of a person you think is doing it, some people might react with violence.
"The troll thing is in an abstract world, but increasingly what they do is crossing over into the real world."
In the documentary Bacon also tracks down Colm Coss, who was jailed for 18 weeks in October 2010 for posting obscene messages on Facebook sites in memory of dead people, including Big Brother star Jade Goody and tribute site to John Paul Massey, a Liverpool boy mauled to death by a dog.
Bacon said he hoped to alert people to the growing problem and how to stop it: "I met two in the show, they are quite intelligent, meek and mild people and some have quite respectable jobs.
"Their power and the thrills they get all come from their anonymity."
He said he thought some trolls saw themselves as "brave", and making dangerous "jokes", but added: "But what they are doing is targeting individuals.
"They know their fellow trolls are watching. You can abuse someone in front of an audience and that's why in the end all it is is bullying.
"Some of these trolls will themselves be deserving of sympathy but that doesn't mean we shouldn't tackle them.
"It's time to stand up to them, it's time to either expose them or if you're a victim go to the police."
The Anti-Social Network airs tomorrow night at 9pm on BBC Three.