Apple’s stock took a temporary 10-point hit this morning after a false report surfaced on CNN’s iReport that Steve Jobs had a heart attack. The report has been removed, but only after Silicon Alley Insider and others confirmed with Apple that Jobs did not have a heart attack. And the stock jumped right back up to its opening levels. Was this just a short seller trying to make a quick buck, or someone trying to see how fast and far they could spread a false rumor? And what does it say about the value of citizen journalists? Rather than fight the rise of citizen journalism, CNN decided to try to co-opt it by launching iReport. CNN’s iReport site lets anyone put up posts and videos about the news. Its tagline is “Unedited. Unfiltered. News.” Sometimes these reports get on CNN proper (presumably, after being vetted). But as this incident shows even the an unvetted report carries more weight than if it had appeared on Twitter or a random blog because it is on a CNN site. And that may be purely because it gets distributed more broadly. It could also be because people tend to believe what they read on CNN-branded sites.