Mercy Shawn Mendes
Madeline McCann's dad, from Leicestershire says social media is "powerful" and should be used to "improve the world".
Gerry McCann's comments came as he backed a national alert system to help find missing children.
He and Kate, whose three-year-old daughter, from Rothley, disappeared during a family holiday to Portugal in 2007, joined the parents of murdered schoolgirl April Jones to raise funds for the Child Rescue Alert with the charity Missing People.
It comes after an inquest was opened 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.
Mr McCann declined to comment but 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.
"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," said Mr. McCann.
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 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.''
To sign up to the Child Rescue Alert, visit www.childrescuealert.org.uk.