Very interesting piece by Sam Bibble at Gawker on Justine Sacco. Sacco was the PR person who tweeted a bit of satire that blew up in her face, and almost destroyed her career.
The problem with Twitter is every post lacks context. You don't know the person to know if they're joking. You haven't seen the build-up to know if the post is ironic, satirical, or a true belief. And it's so damn easy to retweet the actions and reactions, and to get caught up in the rush to condemn. That's the bad, the very horrid part of Twitter.