Storyful is a social media news wire that uses journalistic techniques and standards to verify user-generated content (UGC).
Here's a Medium post that explains the slides below: Verification 101: Storyful’s advice for checking out material from social media, and putting it into practice.
Storyful details the process of verifying Roof's website.
First Draft News is a group of news media partners dedicated to helping reporters find and verify content that emerges online. Their site includes training guides for social media news gathering and verification -- like the above video, for example.