China’s outspoken advocate for sex workers, Ye Haiyan, who once worked as a prostitute for a day to reveal the plight of China’s so-called "10RMB prostitutes", has waged an online battle this week against paedophiles. In a photo that came to inspire hundreds, Ye is seen holding a banner that reads: “Principal, call me if you’d like to get a room, leave the pupils alone.” Ye signed it with her name and "12338”, a national helpline for women. Ye's photo came after news that six primary-school girls were reportedly sexually assaulted on May 8 by a principal and a government official in Wanning, Hainan province. Amid growing anger over widespread sexual abuse of children, Chinese courts have been ordered to mete out harsher sentences to paedophiles . This week, hundreds of activists, police officers, housewives and parents have joined Ye’s battle by posting their own signs featuring the same message to the principal. "Now we can only count on the internet for China's justice," said microblogger Renyutianshi. "We need to pass tough laws to protect our children," many others wrote.