I saw a very good documentary last night called "body without a soul." It's about young boys who for various reasons sell their body on the streets of Prague, Chechnya.
The kids being filmed are very honest about what they do, how they do it and why. Most need money, and have no other place to turn. Suprisingly most are heterosexuals also, and do not enjoy the acts at all. One of them talks about how good it is to fuck little boys who have not yet hit puberty.
The most horrific thing about this piece of film is the porn producer, whom most boys meet sooner or later. He is a chilling piece of work, cuts up bodies for a living at the coroners during the day then during nights and weekends he shoots gay porn with young boys.
http://www.imdb.com/title/tt0115722/
This is one of those docus that we all need to watch. It taught me alot and it shows the dark side of human nature.
I found this page where they list some similar movies.
http://community.middlebury.edu/~moss/EEFilms.html