You can't do anything about anything libelous you might have already posted, just like you can't do anything about any banks you might have robbed in the past.
Eventually the statute of limitations will protect you.
The chances of anyone here getting sued are pretty minimal, unless it's an orchestrated attack by the Democrat party. While there have been many attacks on individuals that might be judged libelous, almost all fall into the category of being somewhat debatable, or expressions of opinion. And then there's the question of whether someone's reputation has truly been damaged as a result of the post. How can Bill Clinton's reputation be hurt at this website?
Like it or not, people are skating on thinner ice on the Schiavo threads. The ice isn't much thicker on the Kobe threads or the Laci Peterson threads. In a lot of instances, posters here are risking a suit which they could lose.
It probably won't happen, simply because it won't be noticed, or the amount of the award recoverable isn't worth the trouble of filing a suit.
But it remains a possibility. Nobody is immune to a libel suit simply because they're posting under a screen name.
Have you ever been to an anti-Bush site? OMG. We're saints.
Excuse me for putting that in big bold lettering, but maybe some IMO hard-headed Freepers will take a hint since you are posting this information since they obviously don't believe CP!