Take, for example, the recent Sunday Times story, which I saw echoed all over the web, saying that Richard Dawkins was going to try to arrest The Pope when he visits the UK.
Here's a quote from Mr Dawkins himself:
Marc Horne, the Sunday Times reporter, telephoned me out of the blue and asked whether I was aware of the initiative by Geoffrey Robertson and Mark Stephens to mount a legal challenge to the Pope's visit. Yes, I said. He asked me if I was in favour of their initiative. Yes, I said, I am strongly in favour of it. Beyond that, I declined to comment to Marc Horne, other than to refer him to my 'Ratzinger is the Perfect Pope' article here: http://richarddawkins.net/articles/5341
How the headline writer could go from there to "Richard Dawkins: I will arrest Pope Benedict XVI" is obscure to me.
Sadly, it's not obscure to me. The process is "That quote wasn't nearly exciting enough, I'll just make shit up."
The next time someone says "We need newspapers because their system of editors and their reputation make them more trustworthy than bloggers." I'm going to laugh in their face.
(cheers to supergee for the link to Dawkins' response)