I'm a little torn on USADA and WADA. I think agencies monitoring performance enhancing drugs should exist, but USADA and WADA is notoriously selective in their scrutiny.
USADA has been trying to gain traction and popularity over the years, and most notably hit the motherload over the Lance Armstrong witch hunt. This isn't to say that Armstrong was in the right to blood dope, but the ferocity in which they went after him, and him alone, in a sport awash with performance enhancing drugs, highlights what they are really after. It's kind of like drug dealing -- they allow the small dealers a little leeway to go after the big fish. Armstrong was the prized hog. And ever since they finally figured out his scam, USADA has managed to legitimize themselves through that scandal. As a result, they have segued in to other professional sports, like Mixed Martial Arts (MMA).
A number of MMA fighters have been caught taking Testosterone Replacement Therapy (TRT) and other enhancers. As a result, many have been suspended from sanctioned competitions for a year or two, at the most. In an absolutely bizarre twist, a fighter named Nick Diaz tested positive for marijuana and was suspended FOUR years, which pretty much means he will probably never compete again and which cuts in to his ability to make money.
This demonstrates a selective bias. That marijuana could be deemed a performance enhancing drug at all is laughable on its own, but to think that it is somehow worse than TRT, which absolutely is a performance enhancer, demonstrates a clear bias.
USADA and WADA are out to legitimize themselves. The more exposure they have, the more business they generate by having other sports accepting them as the official regulatory agencies. And ever since catching Armstrong, there has been a huge spike in the amount of competitions they test for with an ever-increasing list of banned substances. Busting people "doping" is how they say, "See? you need us." But at what point does eating a banana become a "performance enhancing drug" based solely on its positive benefits?
For this reason, I am very leery about their motivations and take them with a grain of salt.
"Reason obeys itself; and ignorance submits to whatever is dictated to it" -- Thomas Paine