In a bid to build the confidence of individual players, Hasler encourages his charges to write positive comments about their teammates that he then collates and passes on to them. ''It is simple but powerful, and I have seen the benefits an activity like that has in helping to build an individual's self-esteem and self-confidence,'' Hasler said.

For the next four weeks, NRL players on school visits in Australia, New Zealand, Samoa and Tonga for the 12th Community Carnival will use the ''drop-a-note box'' to help tackle bullying by encouraging students to anonymously write positive comments about their classmates.

''It is amazing what people can achieve through positive affirmation and having our NRL players deliver that message is also a powerful tool,'' said Hasler, who was a school teacher before beginning his coaching career at Manly in 2004. ''Bullying can occur in so many forms and on so many levels. There is no place for bullies - on or off the football field.''

The NRL launched the ''Tackle Bullying'' campaign on Thursday, with a DVD that features Hazem El Masri, Andrew Ryan, Nathan Hindmarsh and Mario Fenech. Media personality Charlotte Dawson also joined NRL interim chief executive Shane Mattiske and a quartet of players - Manly's David Williams, Cronulla's John Morris, Penrith's Josh Mansour and Parramatta's Kaysa Pritchard at Rugby League Central.

Dawson, who tried to commit suicide after being targeted by ''Twitter trolls'' last year, said that having an entity such as the NRL involved would ensure the anti-bullying message reached a large number of people.

''I have just got back last night from touring to help choose girls for the next series of Australia's Next Top Model and twice these girls got up on stage to audition and said, 'Do you remember me? I picked a fight with you on Twitter. I thought you would remember me','' Dawson said.

''It was the most extraordinary thing, but this abuse is what some of these kids think will get them attention. It is that mindset that needs to change and I think the most important thing is kids listen to these guys, they listen to their heroes, so the reach is so big and the message so powerful that I think it is really going to help and make a difference.''

NRL player welfare manager and education programs manager Nigel Vagana has previously worked with the Australian Federal Police to combat cyberbullying in Samoa and Tonga, and Warriors players will reinforce the message when they visit the island nations. ''It is once they go home from school that most of the terror happens to these kids online,'' Dawson said.

''A lot of parents are out working and these kids are babysat by Facebook and Twitter and other forums and they are allowed to run riot on them.

''No one knows what the trigger points are. In my personal situation I had mental illness for 12 years and this has not been my first experience with hospitalisation for self-harm and suicide attempts. It was an appalling situation and I remember lying in the hospital thinking someone has got to do something about this so it is great that the NRL have started this campaign.''