Go back in time a few months, and it looked as if neither Rick Perry, Paul Ryan, or Chris Christie would run for president this year. Now Perry is full-blown candidate, Paul Ryan is reportedly thinking about entering the race, and according to a tweet by reporter Jonathan Alter, Chris Christie is "conducting focus groups in preparation for a possible run for president in 2012."
Christie has denied that he's going to run for president ad nauseam, and has even threatened to kill himself to prove it, so even the slightest shift from Christie would send shock waves (not a fat joke) through the presidential race. Indeed, Alter's tweet was re-tweeted hundreds of times and was picked up by dozens of news outlets, many of them containing flat denials that any such focus group existed. In fact, not long after sending out his first tweet, Alter backed down from his own bombshell scoop. False alarm everyone!
Here we have a perfect example of one of the pitfalls that occurs when reporters rush to throw their scoops up on Twitter. If Twitter didn't exist, for example (can you even picture that world anymore?), Alter would have heard from these "sources" about the existence of a focus group, then sought out confirmation from his "v-reliable" source close to Christie, who would refute the claim. Since Alter clearly trusts this source much more than the others, he probably wouldn't have written the story at all, or maybe he would have written a much more skeptical story, one that didn't throw the entire political world into commotion.