This is all becoming a big talk about politics, but let's put this simply:
Tom is an Olympic Athlete.
The Riley person isn't.
Therefore, said Riley person is neither as skilled of an athlete nor as talented, and therefore has no right to criticize Tom's performance, ibso facto Riley can go "Suck on that"
As far as gov't involvement, I agree policing for non threatening comments is wrong, but there is a reason that threats are taken seriously by authorities: Either the threatener will make good on said threats, or the threatened will take any and all appropriate actions to protect themselves from said threat.
Are 9/10 threats empty? Yes, but since we're quoting rhymes we heard as children, "One bad apple spoils the bunch", and one moron wrecks things for the rest of us.
Edit: Also (at memadmax), My dad died back in '09, and I have 0 tolerance for anyone who doesnt know him smack talking him (face to face, obviously can't really do anything over the net yet). It takes a real coward to talk smack from behind a computer screen, and while Tom may not have won the gold, Riley had no right to lash out in the way that he did.