When baseball players refuse to talk to Sen. George Mitchell about steroid use and refuse to name names of players they think might be juicing, they're selfish and wrongheaded, on the side of the cheaters and the villains.
When basketball player Josh Howard mentions that he knows lots of NBA players occasionally indulge in ye old wacky tobaccky, he's castigated by Fred Coleman for throwing other players under the proverbial bus. (Note: That bus is running late; Pedro Martinez is still scraping Grady Little out of the tire treads.)
So, to repeat, if you play a major sport and you know that your peers are indulging in an illegal substance, you will get slammed for either coming forward or not coming forward. Bear that in mind, would you?