It's a pattern we've seen before and will likely see again. Often during the Clinton presidency, stories embarrasing to the administration - many of them with no basis in reality - were written about in the British press with little to no actual sourcing then highlighted by domestic conservative outlets as if there was some validity to them. This would then infect domestic discourse and prompt reporting from U.S. news outlets about the invented stories. To call this sort of behavior shoddy journalism is almost generous.
Today's example is this story from the London Telegraph, headlined “Barack Obama furious at General Stanley McChrystal speech on Afghanistan”. Who does the story cite for its evidence of President Obama's allegedly “furious” state? "[S]ources close to the administration", an “adviser to the administration”, "[s]ome commentators" and “critics”. Even those anonymous sources discuss differing views on policy, not the supposed events the article's hook relays. No named sources, or even administration sources, support the headline's contention about the President's supposed emotional state.
Predictably conservative bloggers are taking the ball and running down the field.