I was watching The Tyra Banks show today, and they did an episode about the Tape Worm diet.
A guy who sells tapeworms on the black market went was on that show, and it was very easy to find his website. He claims that it's for autoimmune disorders, not weight loss... but yeah, look at the site name. He also has another site that you go to for the treatment (in Mexico).
In order to obtain the tapeworms, he goes to villages in places like Africa, looks in poo, infects some cows with the worm eggs, then slaughters the cow and harvests the cysts for human consumption. Ew.
Something creepy that made me chuckle is that they warned against taking cocaine and having tapeworms at the same time. It's an "unacceptable risk" to the tapeworm... Does this also mean taking cocaine is a cheap way to get rid of tapeworms? Hmm...