BBC College of Journalism Blog - A vigorous and robust discussion about journalism from every perspective.

The Daily Mail discovered that you really shouldn't believe everything you read after it ran a story online claiming that the new iPhone 4 could be recalled due to technical problems.

The story appeared to be sourced to a Tweet from the account of a certain @ceoSteveJobs. Unfortunately, it wasn't the Steve Jobs, CEO of Apple. What's more, the Twitter biog even included a subtle hint that this was a parody account (the words "of course this is a parody account"). The Tweet was a hoax and the story was completely untrue.

Now it would be easy to have a hubristic pop at the Mail for its gullibility - but pretty much everyone has made similar, if not bigger, howlers. The BBC, for instance, issued a rare on-screen apology when it ran a picture it claimed to be of the devastation caused by Cyclone Nargis in Burma in 2008 which on closer inspection turned out to be of Aceh, Indonesia, following the 2004 Tsunami.

(Although, as an aside, it was disappointing that the Mail chose to remove the offending item from its site rather than openly and honestly admit its mistake - as the Guardian has done this week with a different story.)

The point, however, is about how journalists and journalism respond to the challenges posed by the democratisation of the news process by social media.

In old money, if a journalist walked into a pub and was told by a guy he'd never met that Apple was going to recall its latest iPhone, before he got anywhere near running the story he would a) not believe him b) want to check his bone fides and c) check it out with other sources - not least Apple itself.

It's no different on the web: what the Mail did with the Apple story was ignore basic and old-fashioned principles of good journalism that are as important in the virtual world as they are in the real world.

Of course, it's very tempting to want something to be true and seeing it on a screen does, somehow, make it easier to believe. But stuff you read on the web is no more or less reliable than stuff you're told in real life. Journalists need to authenticate and verify, cross-check and question, before they publish.

The amount of valuable information - as well as gossip and rumour - that is now available on the web means that journalists have to be equipped with the tools to find it and filter the good from the bad. Many big news organisations, including the BBC, have been training their reporters how to do that and how to approach the information they find.

The big, and obvious, lesson for journalists is that, if you don't check rigorously and get it wrong, you will, inevitably, get found out, because someone somewhere will know more than you. They just will. And if you do get it wrong, not only will they tell you, they'll tell everyone else as well, damaging your credibility and your reputation.