Because the dems have a habit of planting false "ordinary citizens" when they are planning an event. Remember the 2000 Florida election protests in West Palm, when 'ordinary voters' who claimed to have problems reading the ballots (and were interviewed as such by the major TV media) turned out, with a little detective work, to be veteran lifelong democratic activists?
Here on FR, for example, I spotted a story where a "man on the street" type was quoted as saying that he was selling his stock in some company (I've since forgotten) in protest of some action taken by a republican. Well, I recognized the name, did a little research, and found out (and posted the results here) that the guy was a major republican activist and was the same person who helped Clinton silence one of his bimbo conquests who was threatening to go public, by offering her a Hollywood acting job.
So, there's a pattern here, and Ann is on to it.