A Twitter hate mob forms very quickly and disperses equally quickly as Justine Sacco found out in December 2013. A new article from Jon Ronson, writing in the New York Times magazine, describes the virtual horror faced by the unsuspecting victims of an internet pile-on.
He also links to a public apology from Sam Biddle of Gawker Media, who initially gave widespread publicity to the original tweet.
The internet is a depressing place sometimes. Quick to anger, petty and vindictive.