Dive summary:

• The Tumblr page “Is Twitter Wrong?” was launched by an MSN international editor in August to check the accuracy of tweets.
• The page's fact checking was initiated in response to fake Mars Rover photos in August.
• A cooperative was formed between “Is Twitter Wrong?” and “The Atlantic” during Hurricane Sandy to analyze weather content.

From the article:

When you’re looking at the basics of fact-checking and making sure false rumours don’t multiply, it really has to be a mass participation activity.