Kate and Gerry McCann, whose daughter Madeleine disappeared from a holiday flat in Portugal 10 years ago, talk during a BBC TV interview. Photo / AP
The parents of Madeleine McCann are urging supporters to help stop trolls who continue to plague them with vile web abuse that they say is "so awful and upsetting".
Kate and Gerry, who face fresh agony as the police hunt into their daughter's disappearance is set to be shelved next month, have approved a set of rules to help curb the online haters, the Daily Mail reports.
The couple told recently how they still try to shield their 12-year-old twins from cruel, false and libellous taunts being made against the family, which Kate describes as "shocking, striking and quite hard to get your head round".
Now the McCanns, whose daughter was snatched from a Portuguese holiday resort 10 and a quarter years ago, are pleading with wellwishers not to post anything to encourage tormentors.
It comes as the UK Government launches a crackdown on online abusers.
The Crown Prosecution Service has revised its guidelines and is now pressing for the growing trend in cyberspace hate to be treated as seriously as face to face abuse.
Kate and Gerry are backing a new Rules of the Road on the official Find Madeleine Campaign website which promotes positive, helpful comments and is now trying to ban trolling.
The digital co-ordinator, a friend of the couple who runs the Facebook page on their behalf, states: "Please do not feed trolls. Trolls feed on havoc and causing chaos. If we do not feed them they will starve for attention and hopefully spread their hate someplace else."
And in bold red type the unnamed web controller warns: "Please don't post your opinion on leaving children alone. Doing so will result in you being banned. No questions asked."
Three-year-old Maddie vanished from Praia da Luz in May 2007. She had been left sleeping with her younger siblings while her parents dined with pals in a nearby tapas restaurant.
In a TV interview to mark the milestone decade anniversary in May, Kate told how the abuse has been "shocking," adding: "Why would someone in a position of ignorance write that, add to someone's upset? It is so awful and upsetting and it becomes more of a talking point."
Kate, 49, a former GP who has taken up a new medical post, told BBC presenter Fiona Bruce they have "tried to educate Sean and Amelie a little bit because it's not just us that has fallen victim to the downside of social media".
Although she and Gerry try to avoid social media, apart from the Maddie campaign, Kate said: 'We are aware of things that get said because people alert us to them. Our worry is for our children.'
Heart doctor Gerry, 49, added: "We have told them that people are writing things that are simply just untrue and they need to be aware of that. People just need to think twice before what they write."
Among rules on their campaign page are: "Do not use obscene, lewd, lascivious, filthy or excessively violent language.
"Do not harass, insult, taunt, provoke, demean or personally attack other people on the page. Be friendly even if others are not.
"Do not ask questions about the investigation."
The web page, which is endorsed by Kate and Gerry from Rothley, Leicestershire, states: "We ultimately have the say on content and tone. We do not ban on a whim."
"This is not a place for you to post your negative opinions about the McCann family.
"We are not a debate page, nor a place to analyse the investigation. This is a support and information page for Madeleine's family and the Official Find Madeleine Campaign."
It adds: "A heartfelt thank you to each and every one of you for supporting Gerry, Kate, Sean, Amelie and most of all Madeleine. Let's get her home!"
Maddie's parents have just six weeks left of guaranteed funding for British detectives to find their daughter. They are anxiously waiting to find out if Operation Grange, the £12 million inquiry into her disappearance, will be extended with a new cash boost in October.
This is not a place for you to post your negative opinions about the McCann family. We are not a debate page, nor a place to analyse the investigation.
Scotland Yard announced two months ago their "investigation is continuing with focus and determination" but as yet no new significant clues have been unearthed.
As time could be running out for police to solve the case, the family still cling on to a glimmer of hope that Maddie could be found alive. She would now be aged 14.
Met Police have Home Office funding until the end of next month to try to crack the world's biggest child disappearance.
They must submit an application if they need further money during the second half the current financial year, which will then be considered but not guaranteed by a Special Grants committee.
Officers were given an extra £85,000 in April to extend Operation Grange to cover six months amid speculation detectives were closing in on a suspect.
A Scotland Yard force spokesman told MailOnline: "Funding is in place until the end of September. Any details about future funding will be released when appropriate."
A Home Office spokesperson said: "The level of funding provided is a reflection of the wide-ranging and complex nature of the investigation, which the police have deemed necessary to undertake.
"Any further requests from the Metropolitan Police Service will be considered. The resources required are reviewed regularly and, as with all Special Grant applications, careful consideration is given before any new funding is allocated."
Maddie's parents are said to be "buoyed up" and "extremely grateful" by the Met's continuing efforts to find their daughter.
In their latest anniversary message to mark "a decade of pain" they said: "Thankfully there is an active police investigation to try and find Madeleine and bring her abductor to justice."