Prostitution

I was watching Taboo today on National Geographic Channel, and an interesting topic came up.  A lady against prostitution was saying that prostitution, either illegal or legal, was violent in all cases.  Well, if prostitution truly was violent in every single case, then why is prostitution so rampant across the globe?  I understand that some people turn to prostitution as a last resort, but not all people.  Also, if prostitution was violent in all cases, then why does it flourish in the few places around the world where it is legal?  Truly, if such conditions were as violent as it is claimed to be, no one would ever choose to be in this profession.  Violence occurs in every aspect of life, but what makes violence prominent in prostitution?  It is the same things with drugs, it is because it is deemed an illegal act and therefore individuals are more willing to engage in violence because they won't get turned in.  Think about it, if you were to get beat up while selling some illegal substances, would you be willing to go to the authorities and say "I got mugged while I was selling dope"?  Of course not, and people know this.  I'm not saying that I'm for or against prostitution, all I am saying is that there is violence innately built into "illegal" acts and through legalization, it is easier to monitor and control all parties involved.