A worldwide network of crime-fighting nuns known as Talitha Kum are expanding their operations from 80 to 140 countries around the globe, Reuters reports.

The nuns are known to go undercover as prostitutes in order to infiltrate brothels and root out instances of human trafficking. That often means purchasing the victims, some who have been sold into the sex trade by their parents, from their captors.

With an estimated 73 million people trafficked globally (half of those aged 16 or younger), Talitha Kum chairman John Studzinski said the need was there to expand the operations of the 1,100 sisters, who also funded a network of homes to provide refuge to victims in the Philippines, India and Brazil.

Via Huffington Post:

"They work in brothels. No one knows they are there," Studzinski said. "These sisters do not trust anyone. They do not trust governments, they do not trust corporations, and they don't trust the local police. In some cases they cannot trust male clergy."

The sisters are also working against slavery and have reportedly gone undercover into factories and worked alongside people making pennies per hour in order to expose those slave-labor conditions.