That line is very thin. Both trafficking and prostitution are against the law and usually, both involve the same BCD type activities.
While there are plenty of ladies who do this of their own free will, there are more that do not, and considering the large overall P4P transactions and very sample size of that video, maybe those particular guys were trafficking.
That is so crazy that they think they can control what people do on their on damn time! They need to go find the losers who are molesting and killing childeren and woman !