The hilarity continues...
Serena Williams: "Stringent enough is putting it mildly. People show up at my
house at five in the morning trying to test me. You never know when they
come. Yeah, I get tested a lot. I don't know about the other players,
but for me it's a pretty intense system, and I know a lot of the players
feel the same way."
Testing has been anything but "intense" for Serena. She was not tested out-of-competition by the ITF or the USADA in either 2010 and 2011. The ITF tested her between 1-3 times in-competition in 2011 and 7+ times in-competition in 2010.
Also, I'd note that Serena says people are "trying to test" her. How often do they succeed?