You throw around a lot of extreme terms like "slander" and "hate crime", but these things simply did not happen.
Anyway, I guess you really meant "libel", and not "slander". In any case, for speech to qualify as slanderous, or libelous, you have to show elements of malice, and possibly that there was damage to his reputation. It might be hard to argue that a poster named "Lick my love pump" actually caused damage to an athlete's reputation.
You also have the wrong expectations about standards of a public forum. Such behavior did happen all the time in pre-internet days, in every bar, and locker room. Was anyone of the public ever convicted for uttering the same kinds of statements? A largely unmoderated forum is a similar cross-section of the public. Do you have any examples where any bar customer, school child, or message board poster was actually convicted for expressing his unfounded opinions about the sexuality or doping of an athlete? I think a conviction of slander or libel in these circumstances is unprecedented in any free country.
Which forums do elite athletes contribute? Actually we might never know how many contribute anonymously. But I think the real reason they don't contribute to this forum is the same reason they don't come to my house or go bowling with me. They have their own life. Why should they mingle with the public? They already have public life, and likely enjoy their privacy when they can.
A Duck wrote:
Free speech doesn't cover slander.
Behavior that has been permitted here, would never be permitted pre Internet.
You're not taking the context of how small this sport is in the USA.
There is indeed a real reason you don't see elite athletes contributing to these forums.