Mumbai shows why social media is useful as a reporting tool. Again.

With every major breaking news story, social media sites and sources keep outdoing themselves. The events in Mumbai have proved to be no exception, with Twitter once again leading the way. Techcrunch notes that Twitter was talking about the terrorist attacks before the media cottoned on to the fact there was something major happening in the Indian City, and says that there's no doubt that Twitter should now be considered a proper news source.

"You can jump up and down and shout all you want that Twitter isn’t a real news source. But all you are doing is viewing the world through a reality lens that’s way outdated. People want information fast and raw from people who are on the scene. If it gets a little messy along the way, that’s ok. We’ll soon see tools that help us distill the really good stuff out of the stream anyway."

Global Voices back this up and goes as far to say that Twitter gives a better sense of what's happening on the ground than traditional media could do.

"While the TV and media reports have been accused of using sensationalism and inflicting more terror from rumors, the twitter feeds portray the real sense of what is happening and how people are coping with it"

Twitter's accuracy as a news source is picked up on in both posts, but it's worth noting that with any breaking news, the exact story can often be unclear. I've worked on or followed numerous breaking stories where the information is contradictory, and what is taken as fact one hour can be shown up as utter garbage the next.

That isn't necessarily the fault of the media or journalists - it just reflects the chaotic nature of breaking news, as do Twitter updates. But one of the most valuable aspects of using Twitter as a news source is the immediacy of the Tweets, and the swiftness with which incorrect information is corrected.

How accurate is Twitter? Well, look at the relevant  # channel for any given story and with a small amount of cross referencing, it's easier to built up a picture of which tweets are giving the most accurate picture.

It's not just the 140 character Tweets that make Twitter so useful for breaking stories. As Duffman notes, video-streaming applications like 12 Seconds, Seesmic, Phreadz, and Qik all post to Twitter feeds direct from a mobile.

"It’s this element of citizen journalism that some professional hacks may not like because they’ve become so used to using news wires to break stories that all they have to give them an edge over the rest of us is the quality of the coverage. Others recognise its potential and get involved.

Twitter empowers citizen journalists and allows them to not only report on on the spot but more importantly, enables them to reach a huge audience. Its not a complete solution as it lacks the objectivity in the same way embedded journalism does. However, it doesn't go through the usual news media prism and is received without being framed to suit anyone else's agenda. That, for me is its true value."

It's not just Twitter that was a useful news source for the Mumbai attacks. Charles Arthur reports that Flickr - the photo sharing site - quickly got a stream of pictures up direct from the scene (and it's pretty hard to question their authenticity).

There's also been Google maps mashups, along with the more traditional source of blogging and an ever-changing Wikipedia page. Journalism.co.uk and The Guardian have good roundups.

It doesn't take a genius to work out that anybody who tracks the right topics across these platforms will be able to pull together a pretty accurate picture of how the story's unfolding - a picture that may well be more accurate than news being reported through more traditional outlets.

This is something that became readily apparent during my tracking of the Exeter bomb blast in Giraffe earlier this year and has already grown beyond my findings back then.

Tracking the story via social media is, of course, no substitute for being on the ground. But if you've got a reporter liaising frequently with a colleague who's pulling in as much information as possible from social media (and other sources), that can produce some impressive journalism.

What's also fascinating is that for the Mumbai terror attacks, most major news websites were liveblogging. It shows how online reporting has moved on in just a few years. When Nosemonkey liveblogged the 7/7 bombings, much of the mainstream media treated it as an interesting curiosity. Now, a liveblog for a major news event - complete with links to other blogs, Twitter feeds, maps mashups, and the like - is pretty much industry standard.

With each major news event, it becomes clear that social media often has the most immediate coverage - and it's a foolhardy journalist who chooses to ignore this.

That said, while social media may be the place to start looking for news during the event and in the immediate aftermath, once it comes to taking the story on and providing richer background analysis, traditional media comes back into its own. It has the time and the resources to devote to journalism.

What events like the Mumbai terror attacks show is that we all have the potential to be online citizen journalists. It's never been easier to get breaking news out on the web - all you need is a half-decent mobile phone.