Sextortion was invented by one woman in the Philippines, Maria Caparas.
They may look like ordinary posts of exotic pets for sale on social media.
Drugs, guns, counterfeit documents and much more are sold on dark web marketplaces that run on anonymous browsers and using cryptocurrency.
Hiding behind the anonymity, the creator of child pornography group Loli Candy and its 7,000 members hid their activities on Facebook and Whatsapp.