The parents of murdered five-year-old April Jones have revealed they were subject to vile abuse from online bullies as they joined with the parents of missing Madeleine McCann to raise funds for the Child Rescue Alert.
Gerry McCann, the father of missing Madeleine, said that despite the endless abuse his family had received, social media is "powerful" and should be used to "improve the world".
Coral and Paul Jones called on Twitter and Facebook to do more to tackle internet trolls after they received "horrible" abuse online following the death of their five-year-old daughter who was kidnapped and murdered in October 2012.
Asked whether they had sympathy with Madeleine's parents who have previously voiced concerns about online abuse, Mrs Jones said: "We've had some ourselves and it took to going in the press and on the news to get it taken off.
"It is horrible, the people that do it."
Questioned on whether police could do more to tackle online trolls, she replied: "It's the internet people as well because the police can't do everything. They should have their own policing force of some sort to do that, with legal ways to prosecute people."
Gerry and his wife Kate McCann, whose three-year-old daughter disappeared during a family holiday to Portugal in 2007, joined the parents of murdered schoolgirl April to raise funds for the Child Rescue Alert with the charity Missing People.
It comes after an inquest was opened today into the death of Brenda Leyland, whose body was found in a hotel room two days after she featured in a Sky News report exposing internet "trolling" of the McCanns.
The McCanns said social media was an important tool for the Child Rescue Alert, a UK-wide system which uses email, text messages and websites including Twitter to try to secure the safe return of missing children.
Mr McCann said: "The key thing about social media is it's powerful. This is a way of using it to do good. That's what we should be using these powerful technologies for - to try and improve the world.
Asked whether they felt it was right for the media to identify internet trolls, Mr McCann replied: "I don't really want to talk about trolls, we're here very much to talk about child rescue."
Actor Hugh Grant, former newsreader Sir Trevor McDonald and presenter Fiona Phillips were among the guests at a dinner organised by Missing People to raise funds for the Child Rescue Alert.
Mrs Jones said she is still struggling to come to terms with her daughter's death. Mark Bridger was given a whole life sentence after he was convicted of April's abduction and murder and of perverting the course of justice by unlawfully disposing, destroying or concealing her body.
April had been playing with friends close to her home on the Bryn Y Gog estate in Machynlleth, mid-Wales, when Bridger, a former slaughterhouse worker, enticed her into his car. Her body has never been found.
Following the recent two-year anniversary of her daughter's disappearance, Mrs Jones said: "I'm still struggling now to this day. We take each day as it comes. Everybody's different in how they cope. Me, personally, I take each day as it comes.
"Some days are better. My husband takes it different, my kids take it different."
Mr Jones added: "I have days where I'm absolutely fine. Two or three days on the trot. Then I have down days. I need to keep busy."
Mrs McCann said she believed the Child Rescue Alert could make "a huge difference" in finding missing children.
"You only have to look at the statistics to see how the amber alert in the USA has been successful - 685 children have been found alive and reunited with their families since it started," she said. "I believe the Child Rescue Alert system could do the same here."
Mr McCann added: "I think it's an opportunity, the Child Rescue Alert, for the British public to help. In our case, there was a great outpouring of people wanting to help. It only takes one person coming forward, responding to that piece of media, that could save a child's life and nothing can be more important."