What do Liam Hemsworth, Chris Hemsworth and Zac Efron have in common? Other than being Hollywood's biggest draws, the actors are painting a fingernail to join the Polished Man movement and raise awareness about physical and sexual violence against children.

The challenge is to paint a nail, post a photograph on social media, and donate to the cause to help raise awareness for the one in five children worldwide who will be the victims of sexual violence in their lifetime.

The idea came about when Elliot Costello, Chief Executive Officer of Australian non-profit organisation, Youth Generation Against Poverty, met a young Cambodian girl who had been abused during her time in an orphanage. The interaction with the girl left a strong impact on Costello. He decided to encourage celebrities to paint a single fingernail to raise awareness and funds worldwide. The painted nail is to be a conversation-starter which will, it is hoped, lead to donations and change.

Launched in 2014, the movement is not restricted only to men – women are encouraged to contribute to the cause as well. But the male focus is driven by the statistic that 90% of all sexual assaults against children are carried out by men.

The campaign has generated over $5,13,000 in donations so far.

The website claims that all the funds raised through Polished Man are "channelled into trauma recovery and trauma prevention programs for children who have suffered or are at risk of suffering violence globally."

Here are some of the men who have attempted the challenge.