Three Canadian teenage girls sporting pigtails and smart attire on Monday pleaded not guilty to forcing fellow suburban teens into prostitution. Police say the trio, who were 15-16 years old when they were arrested last June, acted on their own without adult guidance in operating a prostitution ring from the home of one of their parents. They face 74 charges, including human trafficking and forcible confinement, making and distributing child pornography, assault and sexual assault, uttering threats and theft. The names of the accused and their alleged victims cannot be released under Canadian law. One of at least three female victims was 13 years old. Police said they had been lured through social media to a residence in a middle class neighborhood in Ottawa, abducted and delivered up to adult clients.