The BBC's policy has never been to be the quickest but to be he most accurate. People trust BBC News in a way they don't trust other organisations so I think it's completely right for them to have to check facts before they tweet a story. The Guardian article has a misleading title because the policy is to tell your colleagues before you break a story on Twitter, not to just not break it on Twitter at all.During the August riots the editor of BBC Radio Sheffield retweeted someone saying "We're hearing reports of rioting in Sheffield"...there were no riots in Sheffield. The audience were furious! It could even have lead to police resources being diverted away from where they were needed because people trust the BBC.

So in defence of the BBC's policy - it's just applying the same rigour to tweeting as you would to broadcasting, because tweeting IS broadcasting.As for Sky News's policy I haven't actually seen it but I'm sure they have good reasons for it or the policy has been misquoted (as often happens),