Social media is where facts go to die, and lies go to live. That doesn't mean there isn't data there, but, it needs a lot of smart filtering to be useful.
The problem with social media is low information to noise ratio and given the sheer amount data available it becomes quite difficult to mine the relevant information. Also the rapid pace at which new information enters the system makes the task much more tedious. The media and other sources in their quest to provide news at the earliest more often than not compromise on the accuracy and/or authenticity of the news.
And finally the verification issue, last week who would have thought that the AP news on white house attack was a hoax (due to account hacking) and not a true.