High-profile Australians have come forward with stories about their own Twitter abuse.
Singer Guy Sebastian says he has been a victim of cyber bullies.
"Everyone gets it. I just try to block it. I block people that have a go for no reason. It does affect you though," Sebastian told an eastern states newspaper.
"It isn't nice reading stuff about yourself. People create accounts just to criticise you," he told The Sunday Telegraph.
TV presenter Samantha Armytage said she suffered days of abuse on Twitter. "Trolls have threatened to put my credit card details, home phone number and address on the internet. They were absolutely vile. It was days of abuse. They were all anonymous, which is so gutless."
Former Prime Minister Kevin Rudd said his wife, Therese, has also been the victim of `ugly' online tirades.
"When I have read ugly and abusive attacks on my wife Therese, always from the coward's castle of anonymity, it does make your stomach turn," Rudd told the newspaper.
The well-known Australians have come forward ahead of a TV interview with TV celebrity Charlotte Dawson, who was admitted to hospital with depression on Thursday after she received a torrent of abuse via Twitter.